P1484-种树

约定不等于承诺〃 2023-06-01 08:55 13阅读 0赞

1 #include <bits/stdc++.h>
     2 #define _for(i,a,b) for(int i = (a);i < b;i ++)
     3 #define _rep(i,a,b) for(int i = (a);i > b;i --)
     4 #define INF 0x3f3f3f3f
     5 #define MOD 1000000007
     6 #define pb push_back
     7 #define maxn 500003 
     8 typedef long long ll;
     9 using namespace std;
    10 inline ll read()
    11 {
    12     ll ans = 0;
    13     char ch = getchar(), last = ' ';
    14     while(!isdigit(ch)) last = ch, ch = getchar();
    15     while(isdigit(ch)) ans = (ans << 1) + (ans << 3) + ch - '0', ch = getchar();
    16     if(last == '-') ans = -ans;
    17     return ans;
    18 }
    19 inline void write(ll x)
    20 {
    21     if(x < 0) x = -x, putchar('-');
    22     if(x >= 10) write(x / 10);
    23     putchar(x % 10 + '0');
    24 }
    25 ll N,K;
    26 struct Tree
    27 {
    28     ll id;
    29     ll val;
    30 };
    31 struct cmp
    32 {
    33     bool operator() (const Tree a,const Tree b) const
    34     {
    35         return a.val < b.val;
    36     }
    37 };
    38 priority_queue<Tree,vector<Tree>,cmp> pq;
    39 ll a[maxn];
    40 ll l[maxn],r[maxn];
    41 ll vis[maxn];
    42 ll ans = 0;
    43 int main()
    44 {
    45     N = read();
    46     K = read();
    47     _for(i,1,N+1)
    48     {
    49         a[i] = read();
    50         l[i] = i-1;r[i] = i+1;
    51         pq.push({i,a[i]});
    52     }
    53     
    54     _for(i,0,K)
    55     {
    56         Tree tmp = pq.top();
    57         while(vis[tmp.id])
    58         {
    59             pq.pop();
    60             tmp = pq.top();
    61         }
    62         if(tmp.val<=0)
    63             break;
    64         pq.pop();
    65         ans += tmp.val;
    66         pq.push({tmp.id,a[l[tmp.id]]+a[r[tmp.id]]-tmp.val});
    67         a[tmp.id] = a[l[tmp.id]]+a[r[tmp.id]]-tmp.val;
    68         vis[l[tmp.id]] = vis[r[tmp.id]] = 1;
    69         l[tmp.id]=l[l[tmp.id]];r[l[tmp.id]]=tmp.id;
    70         r[tmp.id]=r[r[tmp.id]];l[r[tmp.id]]=tmp.id;
    71     }
    72     write(ans);
    73     return 0;
    74 }

转载于:https://www.cnblogs.com/Asurudo/p/11564116.html