CODEFORCES-PROBLEMSET 悠悠 2021-12-24 03:43 264阅读 0赞 [1A][] 水题 然而看不仔细爆int了 c++ ![ContractedBlock.gif][] ![ExpandedBlockStart.gif][] 1 #include <bits/stdc++.h> 2 using namespace std; 3 typedef long long ll; 4 int main(){ 5 double n, m, a; 6 cin >> n >> m >> a; 7 ll ans = ll(ceil(n / a)) * ll(ceil(m / a)); 8 cout << ans << endl; 9 return 0; 10 } py3 ![ContractedBlock.gif][] ![ExpandedBlockStart.gif][] 1 import math 2 t = input().split() 3 n, m, a = map(int, t) 4 print(int(math.ceil(n / a) * math.ceil(m / a))) [1B][] 有毒的模拟水题...... ![ContractedBlock.gif][] ![ExpandedBlockStart.gif][] 1 #include <bits/stdc++.h> 2 using namespace std; 3 4 int main(){ 5 int n; 6 cin >> n; 7 while(n--){ 8 string s; 9 cin >> s; 10 bool flag = false; 11 int i = 0; 12 while(i < s.size() && 'A' <= s[i] && s[i] <= 'Z') ++i; 13 for(; i < s.size(); ++i){ 14 if('A' <= s[i] && s[i] <= 'Z'){ 15 flag = true; 16 break; 17 } 18 } 19 if(flag){ 20 int c = 0; 21 int index = s.find('C'); 22 string ans = ""; 23 for(int i = index + 1; i < s.size(); ++i) c = 10 * c + s[i] - '0'; 24 while(c){ 25 int k = c % 26; 26 if(k == 0){ 27 ans += 'Z'; 28 --c; 29 } 30 else ans += ('A' + k - 1); 31 c /= 26; 32 } 33 reverse(ans.begin(), ans.end()); 34 cout << ans << s.substr(1, index-1) << endl; 35 } 36 else{ 37 int index = 0; 38 string ans = "R"; 39 int r = 0; 40 for(; index < s.size(); ++index){ 41 if('0' <= s[index] && s[index] <= '9') break; 42 r = 26 * r + (s[index] - 'A' + 1); 43 } 44 ans += s.substr(index, s.size()); 45 ans += 'C'; 46 cout << ans << r << endl; 47 } 48 } 49 return 0; 50 } [1C][] mdzz。。。 余弦定理求三角形内角,也是圆上的圆周角,乘以2得圆心角 求三圆心角最大公约数得正多边形每一份的圆心角ang,2\*pi/ang得出边数n 海伦公式+正弦定理得三角形外接圆半径r = (a \* b \* c) / (4 \* s) s = n \* r \* r \* sin(ang) / 2 ![ContractedBlock.gif][] ![ExpandedBlockStart.gif][] 1 #include <bits/stdc++.h> 2 using namespace std; 3 const double eps = 1e-2; 4 double fgcd(double a, double b){ 5 if (fabs(a) < eps) 6 return b; 7 if (fabs(b) < eps) 8 return a; 9 return fgcd(b, fmod(a, b)); 10 } 11 double diameter(double a, double b, double c) { 12 double p = (a + b + c) / 2; 13 double s = sqrt(p * (p - a) * (p - b) * (p - c)); 14 return a * b * c / (4 *s); 15 } 16 int main() { 17 double x[3], y[3], line[3]; 18 for(int i = 0; i < 3; ++i) scanf("%lf %lf", &x[i], &y[i]); 19 for(int i = 0; i < 3; ++i) 20 line[i] = sqrt((x[i] - x[(i+1)%3]) * (x[i] - x[(i+1)%3]) + (y[i] - y[(i+1)%3]) * (y[i] - y[(i+1)%3])); 21 double r = diameter(line[0], line[1], line[2]); 22 double angle[3]; 23 for(int i = 0; i < 2; ++i) 24 angle[i] = acos(1 - line[i] * line[i] / (2 * r * r)); 25 angle[2] = 2 * acos(-1) - angle[0] - angle[1]; 26 double ang = fgcd(angle[0], fgcd(angle[1], angle[2])); 27 printf("%.6f\n", r * r * sin(ang) / 2 * (2 * acos(-1) / ang)); 28 return 0; 29 } [2A][] 模拟水题 略麻烦(说到底是思路不清淅不严谨+弱) ![ContractedBlock.gif][] ![ExpandedBlockStart.gif][] 1 #include <bits/stdc++.h> 2 using namespace std; 3 4 struct info{ 5 string name; 6 int score; 7 }aaa[1111]; 8 map<string, int> game; 9 int main(){ 10 int n; 11 cin >> n; 12 string name, ans; 13 int score; 14 for(int i = 0; i < n; ++i){ 15 cin >> name >> score; 16 aaa[i].name = name; 17 aaa[i].score = score; 18 game[name] += score; 19 } 20 int maxScore = -1; 21 for(int i = 0; i < n; ++i) maxScore = max(maxScore, game[aaa[i].name]); 22 map<string, int> tmp; 23 for(int i = 0; i < n; ++i){ 24 if(game[aaa[i].name] < maxScore) continue; 25 tmp[aaa[i].name] += aaa[i].score; 26 if(tmp[aaa[i].name] >= maxScore){ 27 ans = aaa[i].name; 28 break; 29 } 30 } 31 cout << ans << endl; 32 return 0; 33 } [2B][] 然后就2B了..... 求2最少几个5最少几个然后min(num\_two, num\_five)就是答案 剩下输出路径 ![ContractedBlock.gif][] ![ExpandedBlockStart.gif][] 1 #include <bits/stdc++.h> 2 using namespace std; 3 4 int matrix[1111][1111][2]; 5 int dp[1111][1111][2]; 6 int step[1111][1111][2]; 7 8 void print(int nx, int ny, int k){ 9 if(nx == 1 && ny == 1) return ; 10 if(step[nx][ny][k]){ 11 print(nx-1, ny, k); 12 printf("D"); 13 } 14 else{ 15 print(nx, ny-1, k); 16 printf("R"); 17 } 18 } 19 int main(){ 20 int n; 21 scanf("%d", &n); 22 int zerox = 0, zeroy = 0; 23 for(int i = 1; i <= n; ++i){ 24 for(int j = 1; j <= n; ++j){ 25 int k; 26 scanf("%d", &k); 27 if(k == 0){ 28 zerox = i; 29 zeroy = j; 30 continue; 31 } 32 int numtwo = 0, numfive = 0; 33 while(!(k & 1)){ 34 ++numtwo; 35 k >>= 1; 36 } 37 while(k % 5 == 0){ 38 ++numfive; 39 k /= 5; 40 } 41 matrix[i][j][0] = numtwo; 42 matrix[i][j][1] = numfive; 43 } 44 } 45 memset(dp, 0x3f, sizeof(dp)); 46 dp[1][1][0] = matrix[1][1][0]; 47 dp[1][1][1] = matrix[1][1][1]; 48 for(int i = 1; i <= n; ++i){ 49 for(int j = 1; j <= n; ++j){ 50 if(i == 1 && j == 1) continue; 51 for(int k = 0; k < 2; ++k){ 52 dp[i][j][k] = matrix[i][j][k] + min(dp[i-1][j][k], dp[i][j-1][k]); 53 if(dp[i-1][j][k] < dp[i][j-1][k]) step[i][j][k] = 1; 54 } 55 } 56 } 57 int ans = min(dp[n][n][0], dp[n][n][1]); 58 if(ans == 0) puts("0"); 59 else if(zerox && zeroy){ 60 puts("1"); 61 int nx = 1, ny = 1; 62 while(nx < zerox) ++nx, printf("D"); 63 while(ny < zeroy) ++ny, printf("R"); 64 while(nx < n) ++nx, printf("D"); 65 while(ny < n) ++ny, printf("R"); 66 return 0; 67 } 68 else printf("%d\n", ans); 69 int k = dp[n][n][0] < dp[n][n][1] ? 0 : 1; 70 print(n, n, k); 71 return 0; 72 } [2C][] 模拟退火 先放着 ![ContractedBlock.gif][] ![ExpandedBlockStart.gif][] 1 #include <cmath> 2 #include <cstdio> 3 #include <cstdlib> 4 #include <cstring> 5 #include <iostream> 6 #include <algorithm> 7 using namespace std; 8 typedef long long ll; 9 #define _pow(a) ((a)*(a)) 10 const double eps = 1e-6; 11 12 struct circle{ double x, y, r; }c[3]; 13 double angle[3]; 14 int cx[] = { 0, 0, 1, -1}, cy[] = { 1, -1, 0, 0}; 15 16 double dis(double x1, double y1, double x2, double y2){ 17 return sqrt(_pow(x1 - x2) + _pow(y1 - y2)); 18 } 19 20 double calc(double x, double y){ 21 for(int i = 0; i < 3; ++i) angle[i] = dis(x, y, c[i].x, c[i].y) / c[i].r; 22 double value = 0; 23 for(int i = 0; i < 3; ++i) value += _pow(angle[i] - angle[(i + 1) % 3]); 24 return value; 25 } 26 27 int main(){ 28 double x = 0, y = 0; 29 for(int i = 0; i < 3; ++i){ 30 scanf("%lf %lf %lf", &c[i].x, &c[i].y, &c[i].r); 31 x += c[i].x / 3.0; 32 y += c[i].y / 3.0; 33 } 34 double deviation = calc(x, y); 35 double step = 1; 36 for(int i = 0; i <= 1e5; ++i){ 37 bool flag = false; 38 double xx, yy; 39 for(int j = 0; j < 4; ++j){ 40 double nx = x + cx[j] * step, ny = y + cy[j] * step; 41 double nDeviation = calc(nx, ny); 42 if(nDeviation < deviation){ 43 deviation = nDeviation; 44 flag = true; 45 xx = nx; 46 yy = ny; 47 } 48 } 49 if(flag){ 50 x = xx; 51 y = yy; 52 } 53 else step /= 2.0; 54 } 55 if(deviation <= eps) printf("%.5f %.5f\n", x, y); 56 return 0; 57 } [3A][] 水题 但是大神的代码总是让我amazing,简单清晰直接 ![ContractedBlock.gif][] ![ExpandedBlockStart.gif][] 1 #include <bits/stdc++.h> 2 using namespace std; 3 4 int main(){ 5 char s[3], t[3]; 6 scanf("%s %s", s, t); 7 int a = s[0] - t[0], b = s[1] - t[1]; 8 char c = a > 0 ? 'L' : (a = -a, 'R'); 9 char d = b > 0 ? 'D' : (b = -b, 'U'); 10 printf("%d", a > b ? a : b); 11 while(a || b){ 12 puts(""); 13 if(a) --a, putchar(c); 14 if(b) --b, putchar(d); 15 } 16 return 0; 17 } [3B][] 分开按capacity排序 再维护前缀和 再枚举space为1的船的数量 代码好丑........... ![ContractedBlock.gif][] ![ExpandedBlockStart.gif][] 1 #include <bits/stdc++.h> 2 using namespace std; 3 4 struct vihecle{ 5 int id; 6 int cpa; 7 }p1[111111], p2[111111]; 8 int presum1[111111], presum2[111111]; 9 10 bool cmp(vihecle a, vihecle b){ 11 return a.cpa > b.cpa; 12 } 13 14 int main(){ 15 int n, v; 16 cin >> n >> v; 17 int i1 = 0, i2 = 0; 18 presum1[0] = presum2[0] = 0; 19 for(int i = 0; i < n; ++i){ 20 int t, pp; 21 cin >> t >> pp; 22 if(t == 1){ 23 p1[i1].cpa=pp; 24 p1[i1++].id=i+1; 25 } 26 else{ 27 p2[i2].cpa=pp; 28 p2[i2++].id=i+1; 29 } 30 } 31 sort(p1, p1 + i1, cmp); 32 sort(p2, p2 + i2, cmp); 33 for(int i = 1; i <= i1; ++i) presum1[i] = presum1[i-1] + p1[i-1].cpa; 34 for(int i = 1; i <= i2; ++i) presum2[i] = presum2[i-1] + p2[i-1].cpa; 35 int ans = 0, ii1 = 0, ii2 = 0; 36 for(int i = 0; i <= i1; ++i){ 37 if(i > v) break; 38 int tmp = presum1[i] + presum2[min((v-i)/2, i2)]; 39 if(tmp > ans){ 40 ans = tmp; 41 ii1 = i; 42 ii2 = min((v - i) / 2, i2); 43 } 44 } 45 cout << ans << endl; 46 for(int i = 0; i < ii1; ++i) cout << p1[i].id << " "; 47 for(int i = 0; i < ii2; ++i) cout << p2[i].id << " "; 48 return 0; 49 } [3C][] 恶心的模拟..........讲真......玩起来容易写起来恶心....... ![ContractedBlock.gif][] ![ExpandedBlockStart.gif][] 1 #include <bits/stdc++.h> 2 using namespace std; 3 4 char g[5][5]; 5 int c1, c2; 6 bool f1, f2; 7 8 int main(){ 9 for(int i = 0; i < 3; ++i) scanf("%s", g[i]); 10 c1 = c2 = 0; 11 f1 = f2 = false; 12 13 for(int i = 0; i < 3; ++i) 14 if(g[i][0] == g[i][1] && g[i][1] == g[i][2]) 15 if(g[i][0] == 'X') f1 = true; 16 else if(g[i][0] == '0') f2 = true; 17 for(int i = 0; i < 3; ++i) 18 if(g[0][i] == g[1][i] && g[1][i] == g[2][i]) 19 if(g[0][i] == 'X') f1 = true; 20 else if(g[0][i] == '0') f2 = true; 21 if(g[0][0] == g[1][1] && g[1][1] == g[2][2]) 22 if(g[0][0] == 'X') f1 = true; 23 else if(g[0][0] == '0') f2 = true; 24 if(g[0][2] == g[1][1] && g[1][1] == g[2][0]) 25 if(g[1][1] == 'X') f1 = true; 26 else if(g[1][1] == '0') f2 = true; 27 28 for(int i = 0; i < 3; ++i) 29 for(int j = 0; j < 3; ++j) 30 if(g[i][j] == 'X') ++c1; 31 else if(g[i][j] == '0') ++c2; 32 if(c1 == c2 || c1 == c2 + 1){ 33 if(f1 && f2) puts("illegal"); 34 else if(f1 && !f2){ 35 if(c1 == c2 + 1) puts("the first player won"); 36 else puts("illegal"); 37 } 38 else if(!f1 && f2){ 39 if(c1 == c2) puts("the second player won"); 40 else puts("illegal"); 41 } 42 else{ 43 if(c1 + c2 == 9) puts("draw"); 44 else if(c1 + c2 < 9){ 45 if(c1 == c2) puts("first"); 46 else if(c1 == c2 + 1) puts("second"); 47 } 48 else puts("illegal"); 49 } 50 } 51 else puts("illegal"); 52 return 0; 53 } [3D][] 对于处理中每一个过程都有'('不少于')',将'?'置为')',若'('少于')'则在前面的'?'中拿出转换价值最小的进行转换 ![ContractedBlock.gif][] ![ExpandedBlockStart.gif][] 1 #include <bits/stdc++.h> 2 using namespace std; 3 typedef long long ll; 4 5 int main(){ 6 string s; 7 cin >> s; 8 ll cnt = 0, ans = 0; 9 priority_queue<pair<int, int> > q; 10 for(int i = 0; i < s.size(); ++i){ 11 if(s[i] == '(') ++cnt; 12 else if(s[i] == ')') --cnt; 13 else{ 14 int a, b; 15 cin >> a >> b; 16 ans += b; 17 --cnt; 18 s[i] = ')'; 19 q.push(make_pair(b - a, i)); 20 } 21 if(cnt < 0){ 22 if(q.empty()) break; 23 pair<int, int> p = q.top(); 24 q.pop(); 25 ans -= p.first; 26 s[p.second] = '('; 27 cnt += 2; 28 } 29 } 30 if(cnt) cout << "-1" << endl; 31 else cout << ans << endl << s << endl; 32 return 0; 33 } [4A][] 超级水...... ![ContractedBlock.gif][] ![ExpandedBlockStart.gif][] 1 #include <bits/stdc++.h> 2 using namespace std; 3 4 int main(){ 5 int n; 6 cin >> n; 7 cout << (((n & 1) || n == 2) ? "NO" : "YES") << endl; 8 return 0; 9 } [4B][] 水,随便贪一下 ![ContractedBlock.gif][] ![ExpandedBlockStart.gif][] 1 #include <bits/stdc++.h> 2 using namespace std; 3 4 struct { 5 int mini, maxi; 6 }p[33]; 7 8 int main(){ 9 int d, maxSum; 10 cin >> d >> maxSum; 11 int totalMin = 0, totalMax = 0; 12 for(int i = 0; i < d; ++i) cin >> p[i].mini >> p[i].maxi, totalMin += p[i].mini, totalMax += p[i].maxi; 13 if(totalMin > maxSum || totalMax < maxSum) 14 cout << "NO" << endl; 15 else{ 16 cout << "YES" << endl; 17 int t = maxSum - totalMin; 18 for(int i = 0; i < d; ++i){ 19 int ansi = p[i].mini; 20 if(t){ 21 ansi = min(p[i].maxi, ansi + t); 22 t -= (ansi - p[i].mini); 23 } 24 cout << ansi << " \n"[i == d-1]; 25 } 26 } 27 return 0; 28 } [4C][] 水,输入保证只有小写字母,map水过 ![ContractedBlock.gif][] ![ExpandedBlockStart.gif][] 1 #include <bits/stdc++.h> 2 using namespace std; 3 4 int main(){ 5 int n; 6 cin >> n; 7 map<string, int> name; 8 while(n--){ 9 string s; 10 cin >> s; 11 if(name[s] == 0) cout << "OK" << endl; 12 else cout << s << name[s] << endl; 13 ++name[s]; 14 } 15 return 0; 16 } [4D][] n^2的暴力dp....... ![ContractedBlock.gif][] ![ExpandedBlockStart.gif][] 1 #include <bits/stdc++.h> 2 using namespace std; 3 4 int n; 5 struct env{ 6 int w, h; 7 }p[5555]; 8 int dp[5555], pre[5555]; 9 10 int dfs(int k){ 11 if(dp[k]) return dp[k]; 12 for(int i = 1; i <= n; ++i){ 13 if(p[k].w < p[i].w && p[k].h < p[i].h){ 14 if(dfs(i) + 1 > dp[k]){ 15 pre[k] = i; 16 dp[k] = dfs(i) + 1; 17 } 18 } 19 } 20 return dp[k]; 21 } 22 23 int main(){ 24 cin >> n; 25 for(int i = 0; i <= n; ++i) 26 cin >> p[i].w >> p[i].h; 27 cout << dfs(0) << endl; 28 for(int i = pre[0]; i > 0; i = pre[i]) cout << i << " "; 29 cout << endl; 30 return 0; 31 } [5A][] 水 ![ContractedBlock.gif][] ![ExpandedBlockStart.gif][] 1 #include <bits/stdc++.h> 2 using namespace std; 3 4 int main(){ 5 string s; 6 int ans = 0, member = 0; 7 while(getline(cin, s)){ 8 if(s[0] == '+') ++member; 9 else if(s[0] == '-') --member; 10 else{ 11 int len = s.end() - find(s.begin(), s.end(), ':') - 1; 12 ans += member * len; 13 } 14 } 15 cout << ans << endl; 16 return 0; 17 } [5B][] 一眼样例明白大概但是奇数的情况要交替........ ![ContractedBlock.gif][] ![ExpandedBlockStart.gif][] 1 #include <bits/stdc++.h> 2 using namespace std; 3 4 int main(){ 5 vector<string> v; 6 string s; 7 int len = 0; 8 while(getline(cin, s)){ 9 v.push_back(s); 10 len = max(len, int(s.size())); 11 } 12 cout << string(len+2, '*') << endl; 13 int k = -1; 14 for(vector<string>::iterator i = v.begin(); i != v.end(); ++i){ 15 int l = len - (*i).size(); 16 string fr = string(floor(double(l)/2), ' '), ba = string(ceil(double(l)/2), ' '); 17 if(l & 1){ 18 if(!k) cout << "*" << ba << *i << fr << "*" << endl; 19 else cout << "*" << fr << *i << ba << "*" << endl; 20 k = ~k; 21 } 22 else cout << "*" << fr << *i << ba << "*" << endl; 23 } 24 cout << string(len+2, '*') << endl; 25 return 0; 26 } [5C][] dp,让我智障好久的题........ ![ContractedBlock.gif][] ![ExpandedBlockStart.gif][] 1 #include <bits/stdc++.h> 2 using namespace std; 3 4 const int maxn = 1e6 + 7; 5 int dp[maxn]; 6 7 int main(){ 8 ios::sync_with_stdio(false); 9 memset(dp, 0, sizeof(dp)); 10 string s; 11 cin >> s; 12 stack<int> pos; 13 while(!pos.empty()) pos.pop(); 14 int len = 0, sum = 1; 15 for(int i = 0; i < s.size(); ++i){ 16 if(s[i] == '(') pos.push(i); 17 else if(!pos.empty()){ 18 int j = pos.top(); 19 pos.pop(); 20 int tmpSize = i - j + 1; 21 dp[i] = tmpSize + (j ? dp[j-1] : 0); 22 if(dp[i] > len){ 23 len = dp[i]; 24 sum = 1; 25 } 26 else if(dp[i] == len) ++sum; 27 } 28 } 29 cout << len << " " << sum << endl; 30 return 0; 31 } [5D][] 运动学卧槽......放弃 分类还是渣的不成样子..... ![ContractedBlock.gif][] ![ExpandedBlockStart.gif][] 1 #include <bits/stdc++.h> 2 using namespace std; 3 4 const double eps = 1e-8; 5 double a, v, l, d, w, t1, t2, vd, vt, r; 6 7 int fcmp(double x){ 8 if(fabs(x) < eps) return 0; 9 else return x < 0 ? -1 : 1; 10 } 11 12 int main(){ 13 scanf("%lf %lf %lf %lf %lf", &a, &v, &l, &d, &w); 14 vt = sqrt(w * w / 2 + a * d); 15 r = l - d; 16 if(fcmp(d - v * v / 2 / a) <= 0 && fcmp(sqrt(2 * a * d) - w) <= 0){ 17 t1 = sqrt(2 * d / a); 18 vd = sqrt(2 * a * d); 19 } 20 else if(fcmp(d - v * v / 2 / a) >= 0 && fcmp(w - v) >= 0){ 21 t1 = d / v + v / 2 / a; 22 vd = v; 23 } 24 else if(fcmp(v - vt) >= 0 && fcmp(vt - w) >= 0){ 25 t1 = (2 * vt - w) / a; 26 vd = w; 27 } 28 else{ 29 t1 = d / v + (2 * v - w) / a - (2 * v * v - w * w) / 2 / a / v; 30 vd = w; 31 } 32 if(fcmp(r - (v * v - vd * vd) / 2 / a) >= 0) 33 t2 = r / v + (v - vd) / a - (v * v - vd * vd) / 2 / a / v; 34 else 35 t2 = (sqrt(2 * a * r + vd * vd) - vd) / a; 36 printf("%.10f\n", t1 + t2); 37 return 0; 38 } [5E][] 找每个点左右分别严格高于这个点的点,有点像并查集的样子 还需要找处在中间的相同高度的点 每个点与左右两个高点及相同高度的点可以互相看到 ![ContractedBlock.gif][] ![ExpandedBlockStart.gif][] 1 #include <bits/stdc++.h> 2 using namespace std; 3 typedef long long ll; 4 5 const int maxn = 1e6 + 7; 6 int height[maxn], l[maxn], r[maxn], same[maxn]; 7 ll ans = 0; 8 9 int main(){ 10 int n; 11 scanf("%d", &n); 12 int maxi = -1, pos = 0; 13 for(int i = 0; i < n; ++i){ 14 scanf("%d", &height[i]); 15 if(height[i] > maxi){ 16 maxi = height[i]; 17 pos = i; 18 } 19 } 20 rotate(height, height + pos, height + n); 21 height[n] = maxi; 22 same[n] = 0; 23 for(int i = n - 1; i >= 0; --i){ 24 r[i] = i + 1; 25 while(r[i] < n && height[i] > height[r[i]]) r[i] = r[r[i]]; 26 if(r[i] != n && height[i] == height[r[i]]){ 27 same[i] = same[r[i]] + 1; 28 r[i] = r[r[i]]; 29 } 30 } 31 for(int i = 1; i <= n; ++i){ 32 l[i] = i - 1; 33 while(l[i] && height[i] >= height[l[i]]) l[i] = l[l[i]]; 34 } 35 for(int i = 1; i < n; ++i){ 36 ans += (2 + same[i]); 37 if(l[i] == 0 && r[i] == n) --ans; 38 } 39 printf("%I64d\n", ans); 40 return 0; 41 } [6A][] 水题 ![ContractedBlock.gif][] ![ExpandedBlockStart.gif][] 1 #include <bits/stdc++.h> 2 using namespace std; 3 4 int a, b, c, d; 5 6 void init(){ 7 int arr[4]; 8 cin >> arr[0] >> arr[1] >> arr[2] >> arr[3]; 9 sort(arr, arr + 4); 10 a = arr[0]; b= arr[1]; c = arr[2]; d = arr[3]; 11 } 12 int main(){ 13 init(); 14 if(a + b > c || a + b > d || a + c > d || b + c > d) puts("TRIANGLE"); 15 else if(a + b == c || a + b == d || a + c == d || b + c == d) puts("SEGMENT"); 16 else puts("IMPOSSIBLE"); 17 return 0; 18 } [6B][] 两层广搜过的,然而智障了......用一层广搜+set就行了 两层的辣鸡代码....: ![ContractedBlock.gif][] ![ExpandedBlockStart.gif][] 1 #include <bits/stdc++.h> 2 using namespace std; 3 4 const int maxsize = 111; 5 int cx[] = { 1, -1, 0, 0}, cy[] = { 0, 0, 1, -1}; 6 struct pos{ 7 int x, y; 8 pos(int xx = 0, int yy = 0): x(xx), y(yy){}; 9 }; 10 11 char room[maxsize][maxsize]; 12 bool flag[maxsize][maxsize]; 13 14 int main(){ 15 int n, m; 16 char color; 17 cin >> n >> m; 18 cin.get(); 19 cin >> color; 20 queue<pos> mainpos; 21 memset(flag, false, sizeof(flag)); 22 for(int i = 0; i < n; ++i) 23 for(int j = 0; j < m; ++j){ 24 cin >> room[i][j]; 25 if(room[i][j] == color){ 26 mainpos.push(pos(i, j)); 27 flag[i][j] = true; 28 } 29 } 30 int ans = 0; 31 while(!mainpos.empty()){ 32 int x = mainpos.front().x, y = mainpos.front().y; 33 mainpos.pop(); 34 for(int i = 0; i < 4; ++i){ 35 int nx = x + cx[i], ny = y + cy[i]; 36 if(nx < 0 || n <= nx || ny < 0 || m <= ny || flag[nx][ny] || room[nx][ny] == '.') continue; 37 ++ans; 38 queue<pos> tpos; 39 tpos.push(pos(nx, ny)); 40 flag[nx][ny] = true; 41 char tcolor = room[nx][ny]; 42 while(!tpos.empty()){ 43 int xx = tpos.front().x, yy = tpos.front().y; 44 tpos.pop(); 45 for(int j = 0; j < 4; ++j){ 46 int nxx = xx + cx[j], nyy = yy + cy[j]; 47 if(nxx < 0 || n <= nxx || nyy < 0 || m <= nyy || room[nxx][nyy] != tcolor || flag[nxx][nyy]) continue; 48 flag[nxx][nyy] = true; 49 tpos.push(pos(nxx, nyy)); 50 } 51 } 52 } 53 } 54 cout << ans << endl; 55 return 0; 56 } 一层 + set: ![ContractedBlock.gif][] ![ExpandedBlockStart.gif][] 1 #include <bits/stdc++.h> 2 using namespace std; 3 4 const int maxsize = 111; 5 int cx[] = { 1, -1, 0, 0}, cy[] = { 0, 0, 1, -1}; 6 struct pos{ 7 int x, y; 8 pos(int xx = 0, int yy = 0): x(xx), y(yy){}; 9 }; 10 11 char room[maxsize][maxsize]; 12 13 int main(){ 14 int n, m; 15 char color; 16 cin >> n >> m; 17 cin.get(); 18 cin >> color; 19 queue<pos> mainpos; 20 for(int i = 0; i < n; ++i) 21 for(int j = 0; j < m; ++j){ 22 cin >> room[i][j]; 23 if(room[i][j] == color) 24 mainpos.push(pos(i, j)); 25 } 26 set<char> ans; 27 while(!mainpos.empty()){ 28 int x = mainpos.front().x, y = mainpos.front().y; 29 mainpos.pop(); 30 for(int i = 0; i < 4; ++i){ 31 int nx = x + cx[i], ny = y + cy[i]; 32 if(nx < 0 || n <= nx || ny < 0 || m <= ny || room[nx][ny] == color || room[nx][ny] == '.') continue; 33 ans.insert(room[nx][ny]); 34 } 35 } 36 cout << ans.size() << endl; 37 return 0; 38 } [6C][] 水题,第一次用deque ![ContractedBlock.gif][] ![ExpandedBlockStart.gif][] 1 #include <bits/stdc++.h> 2 using namespace std; 3 4 int main(){ 5 int n; 6 cin >> n; 7 deque<int> chb; 8 for(int i = 0; i < n; ++i){ 9 int tmp; 10 cin >> tmp; 11 chb.push_back(tmp); 12 } 13 int t1 = chb.front(), ans1 = 1, t2 = 0, ans2 = 0; 14 chb.pop_front(); 15 while(!chb.empty()){ 16 if(t1 <= t2){ 17 t1 += chb.front(); 18 ++ans1; 19 chb.pop_front(); 20 } 21 else{ 22 t2 += chb.back(); 23 ++ans2; 24 chb.pop_back(); 25 } 26 } 27 cout << ans1 << " " << ans2 << endl; 28 return 0; 29 } [6D][] 不会做.....题解看不懂....... dfs ![ContractedBlock.gif][] ![ExpandedBlockStart.gif][] 1 #include <bits/stdc++.h> 2 using namespace std; 3 typedef long long ll; 4 const int MAXN = 22; 5 int n, a, b, ans, h[MAXN], hh[MAXN]; 6 7 8 bool dfs(int curpos, int time, int hitpos){ 9 if(time == 0){ 10 for(int i = 1; i <= n; ++i) 11 if(h[i] >= 0) return false; 12 return true; 13 } 14 if(h[curpos] < 0) return dfs(curpos+1, time, hitpos); 15 for(int i = min(n-1, max(hitpos, max(2, curpos))); i <= min(n-1, curpos+1); ++i){ 16 h[i] -= a; h[i-1] -= b; h[i+1] -= b; 17 if(dfs(curpos, time-1, i)){ 18 hh[time] = i; 19 return true; 20 } 21 h[i] += a; h[i-1] += b; h[i+1] += b; 22 } 23 return false; 24 } 25 26 27 int main(){ 28 cin >> n >> a >> b; 29 for(int i = 1; i <= n; ++i) cin >> h[i]; 30 for(int i = 1; ; ++i){ 31 memset(hh, 0, sizeof(hh)); 32 if(dfs(1, i, 2)){ 33 cout << i << endl; 34 for(int j = 1; j <= i; ++j) 35 cout << hh[j] << " "; 36 return 0; 37 } 38 } 39 return 0; 40 } [6E][] 求最大值最小值差不超过给定值的最长子串 ST表预处理区间最大值最小值,加个二分右边界... ![ContractedBlock.gif][] ![ExpandedBlockStart.gif][] 1 #include <bits/stdc++.h> 2 using namespace std; 3 4 const int maxn = 1e5 + 7; 5 int n, k; 6 int data[maxn]; 7 int premin[maxn][20], premax[maxn][20]; 8 struct tpoint{ 9 int l, r; 10 tpoint(int _l, int _r): l(_l), r(_r) {}; 11 }; 12 13 void init_st(){ 14 for(int i = 1; i <= n; ++i) 15 premin[i][0] = premax[i][0] = data[i]; 16 int k = floor(log(double(n)) / log(2.0)); 17 for(int j = 1; j <= k; ++j) 18 for(int i = n; i >= 1; --i) 19 if(i + (1<<(j-1)) <= n){ 20 premin[i][j] = min(premin[i][j-1], premin[i+(1<<(j-1))][j-1]); 21 premax[i][j] = max(premax[i][j-1], premax[i+(1<<(j-1))][j-1]); 22 } 23 } 24 25 int query_st(int l, int r){ 26 int k = floor(log(double(r-l+1)) / log(2.0)); 27 return max(premax[l][k], premax[r-(1<<k)+1][k]) - min(premin[l][k], premin[r-(1<<k)+1][k]); 28 } 29 30 int check(int i){ 31 int l = i, r = n + 1; 32 while(l < r - 1){ 33 int mid = (l + r) >> 1; 34 if(query_st(i, mid) <= k) l = mid; 35 else r = mid; 36 } 37 return l; 38 } 39 40 int main(){ 41 scanf("%d %d", &n, &k); 42 for(int i = 1; i <= n; ++i) 43 scanf("%d", &data[i]); 44 init_st(); 45 int amount = 0; 46 vector<tpoint> vp; 47 for(int l = 1; l <= n; ++l){ 48 int r = check(l); 49 int num = r - l + 1; 50 if(num > amount){ 51 vp.clear(); 52 vp.push_back(tpoint(l, r)); 53 amount = num; 54 } 55 else if(num == amount) vp.push_back(tpoint(l, r)); 56 } 57 printf("%d %d\n", amount, vp.size()); 58 for(vector<tpoint>::iterator i = vp.begin(); i != vp.end(); ++i) 59 printf("%d %d\n", (*i).l, (*i).r); 60 return 0; 61 } [7A][] 水题但是有点意思(因为你还是个渣啊~) 记下每一行每一列多少个黑,凑齐8个答案+1,若答案是16就-8 ![ContractedBlock.gif][] ![ExpandedBlockStart.gif][] 1 #include <bits/stdc++.h> 2 using namespace std; 3 4 char cb[10][10]; 5 int cnt[10][10]; 6 7 int main(){ 8 ios::sync_with_stdio(false); 9 int ans = 0; 10 for(int i = 0; i < 8; ++i) 11 for(int j = 0; j < 8; ++j){ 12 cin >> cb[i][j]; 13 if(cb[i][j] == 'B'){ 14 ++cnt[i][8]; 15 ++cnt[8][j]; 16 } 17 if(cnt[i][8] == 8) ++ans; 18 if(cnt[8][j] == 8) ++ans; 19 } 20 if(ans == 16) ans -= 8; 21 cout << ans << endl; 22 return 0; 23 } [7B][] 粗暴地模拟,大概坑都是给我挖的.... ![ContractedBlock.gif][] ![ExpandedBlockStart.gif][] 1 #include <bits/stdc++.h> 2 using namespace std; 3 4 const int maxn = 111; 5 int n, k, mem[maxn]; 6 7 int main(){ 8 int counter = 0; 9 scanf("%d %d", &n, &k); 10 while(n--){ 11 char s[11]; 12 int x; 13 scanf("%s", s); 14 if(s[0] == 'a' || s[0] == 'e'){ 15 scanf("%d", &x); 16 if(s[0] == 'a'){ 17 bool flag = false; 18 int tmp = 0; 19 for(int i = 0; i < k; ++i){ 20 if(mem[i] == 0) ++tmp; 21 else tmp = 0; 22 if(tmp == x){ 23 printf("%d\n", ++counter); 24 int index = i; 25 while(tmp--) mem[index--] = counter; 26 flag = true; 27 break; 28 } 29 } 30 if(!flag) puts("NULL"); 31 } 32 else{ 33 bool flag = false; 34 for(int i = 0; i < k; ++i){ 35 if(x == 0) break; 36 if(mem[i] == x){ 37 mem[i] = 0; 38 flag = true; 39 } 40 } 41 if(!flag) puts("ILLEGAL_ERASE_ARGUMENT"); 42 } 43 } 44 else{ 45 for(int i = 0; i < k; ++i){ 46 if(mem[i] != 0){ 47 int j = i; 48 while(j > 0 && mem[j-1] == 0) --j; 49 swap(mem[i], mem[j]); 50 } 51 } 52 } 53 } 54 return 0; 55 } [7C][] 扩展欧几里得解不定方程组 ![ContractedBlock.gif][] ![ExpandedBlockStart.gif][] 1 #include <bits/stdc++.h> 2 using namespace std; 3 typedef long long ll; 4 5 ll ex_gcd(ll a, ll b, ll& x, ll& y){ 6 if(b == 0){ 7 x = 1; 8 y = 0; 9 return a; 10 } 11 int k = ex_gcd(b, a % b, x, y); 12 int t = y; 13 y = x - (a / b) * y; 14 x = t; 15 return k; 16 } 17 18 int main(){ 19 ios::sync_with_stdio(false); 20 ll a, b, c, x, y; 21 cin >> a >> b >> c; 22 ll k = ex_gcd(a, b, x, y); 23 c = -c; 24 if(c % k) cout << "-1" << endl; 25 else cout << (c / k * x) << " " << (c / k * y) << endl; 26 return 0; 27 } [7D][] 字符串两个方向hash判回文+dp ![ContractedBlock.gif][] ![ExpandedBlockStart.gif][] 1 #include <bits/stdc++.h> 2 using namespace std; 3 typedef long long ll; 4 5 const int maxn = 5e6 + 7; 6 const int mod = 1e9 + 7; 7 const int tmp = 137731735; 8 char s[maxn]; 9 ll prefix[maxn], suffix[maxn], dp[maxn]; 10 11 int main(){ 12 gets(s); 13 for(int i = 0; s[i]; ++i){ 14 if(s[i] >= '0' && s[i] <= '9') 15 s[i] -= '0'; 16 else if(s[i] >= 'a' && s[i] <= 'z') 17 s[i] -= ('a' - 10); 18 else 19 s[i] -= ('A' - 36); 20 } 21 ll len = strlen(s), base = 1; 22 for(int i = 1; i <= len; ++i){ 23 prefix[i] = (prefix[i-1] + s[i-1] * base) % mod; 24 base = (base * tmp) % mod; 25 suffix[i] = (suffix[i-1] * tmp + s[i-1]) % mod; 26 } 27 ll ans = 0; 28 for(int i = 1; i <= len; ++i){ 29 if(prefix[i] == suffix[i]){ 30 dp[i] = dp[i>>1] + 1; 31 ans += dp[i]; 32 } 33 } 34 printf("%I64d\n", ans); 35 return 0; 36 } [7E][] arhgoiawhengiuehgoaijgioj........ [8A][] 水题,用py3写是因为.....懒...... ![ContractedBlock.gif][] ![ExpandedBlockStart.gif][] 1 s = input() 2 s1 = input() 3 s2 = input() 4 5 forw = backw = False 6 tmp = s.find(s1) 7 if ~tmp: 8 if ~s[tmp+len(s1):].find(s2): 9 forw = True 10 s = s[::-1] 11 tmp = s.find(s1) 12 if ~tmp: 13 if ~s[tmp+len(s1):].find(s2): 14 backw = True 15 16 if forw and backw: print('both') 17 elif forw: print('forward') 18 elif backw: print('backward') 19 else: print('fantasy') [8B][] 啊啊啊啊啊啊啊手贱啊啊啊啊啊啊啊 真·教育题 谢谢(微笑) ![ContractedBlock.gif][] ![ExpandedBlockStart.gif][] 1 #include <bits/stdc++.h> 2 using namespace std; 3 typedef pair<int, int> point; 4 map<point, int> check; 5 int cx[] = { 1, -1, 0, 0}, cy[] = { 0, 0, -1, 1}; 6 int main(){ 7 string s; 8 cin >> s; 9 int x = 0, y = 0, xx = 0, yy = 0; 10 ++check[point(x, y)]; 11 bool flag = true; 12 for(int i = 0; i < s.size(); ++i){ 13 if(s[i] == 'L') --x; 14 else if(s[i] == 'R') ++x; 15 else if(s[i] == 'U') ++y; 16 else --y; 17 for(int i = 0; i < 4; ++i){ 18 int xxx = x + cx[i], yyy = y + cy[i]; 19 if(xxx == xx && yyy == yy) continue; 20 if(check[point(xxx, yyy)]){ 21 flag = false; 22 break; 23 } 24 } 25 if(check[point(x, y)]) flag = false; 26 if(!flag) break; 27 ++check[point(x, y)]; 28 xx = x; yy = y; 29 } 30 cout << (flag ? "OK" : "BUG") << endl; 31 return 0; 32 } [8C][] 状压dp,不需要绝对固定的顺序,所以每次只要取最前面可取的(line34的break),每次拿一个或两个(最里层for从 j 开始) ![ContractedBlock.gif][] ![ExpandedBlockStart.gif][] 1 #include <bits/stdc++.h> 2 using namespace std; 3 const int MAXN = 25; 4 const int INF = 0x3f3f3f3f; 5 struct point{ 6 int x, y; 7 point(){} 8 point(int xx, int yy): x(xx), y(yy) {} 9 }; 10 point p[MAXN]; 11 int n, dp[1<<MAXN], pre[1<<MAXN], dis[MAXN][MAXN], ans[555]; 12 inline int calc(point a, point b){ 13 return (a.x - b.x) * (a.x - b.x) + (a.y - b.y) * (a.y - b.y); 14 } 15 int main(){ 16 cin >> p[0].x >> p[0].y >> n, p[n] = p[0]; 17 for(int i = 0; i < n; ++i) cin >> p[i].x >> p[i].y; 18 for(int i = 0; i <= n; ++i) for(int j = 0; j <= n; ++j) dis[i][j] = calc(p[i], p[j]); 19 memset(dp, INF, sizeof(dp)); 20 dp[0] = 0; 21 for(int i = 0; i < (1<<n); ++i) 22 if(dp[i] != INF) 23 for(int j = 0; j < n; ++j) 24 if(!(i>>j&1)){ 25 for(int k = j; k < n; ++k) 26 if(!(i>>k&1)){ 27 int cur = i | (1<<j) | (1<<k); 28 int tmp = dp[i] + dis[n][j] + dis[j][k] + dis[k][n]; 29 if(dp[cur] > tmp){ 30 dp[cur] = tmp; 31 pre[cur] = i; 32 } 33 } 34 break; 35 } 36 cout << dp[(1<<n)-1] << endl << 0; 37 int cnt = 0; 38 for(int i = (1<<n)-1; i; i = pre[i]){ 39 int tmp = pre[i] ^ i; 40 ans[cnt++] = 0; 41 for(int j = 0; j < n; ++j) 42 if((1<<j)&tmp) 43 ans[cnt++] = j + 1; 44 } 45 for(int i = cnt-1; ~i; --i) cout << " " << ans[i]; 46 return 0; 47 } [8D][] 转载于:https://www.cnblogs.com/book-book/p/5496344.html [1A]: http://codeforces.com/problemset/problem/1/A [ContractedBlock.gif]: https://images.cnblogs.com/OutliningIndicators/ContractedBlock.gif [ExpandedBlockStart.gif]: /images/20211223/ecc0a9fb846447eaa4ea19d540365d47.png [1B]: http://codeforces.com/problemset/problem/1/B [1C]: http://codeforces.com/problemset/problem/1/C [2A]: http://codeforces.com/problemset/problem/2/A [2B]: http://codeforces.com/problemset/problem/2/B [2C]: http://codeforces.com/problemset/problem/2/C [3A]: http://codeforces.com/problemset/problem/3/A [3B]: http://codeforces.com/problemset/problem/3/B [3C]: http://codeforces.com/contest/3/problem/C [3D]: http://codeforces.com/contest/3/problem/D [4A]: http://codeforces.com/problemset/problem/4/A [4B]: http://codeforces.com/problemset/problem/4/B [4C]: http://codeforces.com/problemset/problem/4/C [4D]: http://codeforces.com/problemset/problem/4/D [5A]: http://codeforces.com/problemset/problem/5/A [5B]: http://codeforces.com/problemset/problem/5/B [5C]: http://codeforces.com/problemset/problem/5/C [5D]: http://codeforces.com/problemset/problem/5/D [5E]: http://codeforces.com/problemset/problem/5/E [6A]: http://codeforces.com/problemset/problem/6/A [6B]: http://codeforces.com/problemset/problem/6/B [6C]: http://codeforces.com/problemset/problem/6/C [6D]: http://codeforces.com/problemset/problem/6/D [6E]: http://codeforces.com/problemset/problem/6/E [7A]: http://codeforces.com/problemset/problem/7/A [7B]: http://codeforces.com/problemset/problem/7/B [7C]: http://codeforces.com/problemset/problem/7/C [7D]: http://codeforces.com/problemset/problem/7/D [7E]: http://codeforces.com/problemset/problem/7/E [8A]: http://codeforces.com/problemset/problem/8/A [8B]: http://codeforces.com/problemset/problem/8/B [8C]: http://codeforces.com/problemset/problem/8/C [8D]: http://codeforces.com/problemset/problem/8/D
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