Codeforces Global Round 2（A/B/C）

痛定思痛。 2022-02-22 02:08 129阅读 0赞

这场比赛作出前两道题就挂机了，没有信心做下去了。

题目链接：[http://codeforces.com/contest/1119][http_codeforces.com_contest_1119]

[A. Ilya and a Colorful Walk][]

#include<bits/stdc++.h>
    using namespace std;
    const int maxn=3e5+10;
    int a[maxn];
    int main(){
    	int n;
    	scanf("%d",&n);
    	for(int i=1;i<=n;i++){
    		scanf("%d",&a[i]);
    	}
    	int mx=0;
    	for(int i=1;i<=n;i++){
    		if(a[i]!=a[1]) mx=max(mx,i-1);
    		if(a[i]!=a[n]) mx=max(mx,n-i);
    	}
    	printf("%d\n",mx);
    	return 0;
    }

--------------------

[B. Alyona and a Narrow Fridge][]

#include<bits/stdc++.h>
    using namespace std;
    const int maxn=3e5+10;
    int a[maxn],b[maxn];
    
    
    int main(){
    	int n,h;
    	scanf("%d%d",&n,&h);
    	for(int i=1;i<=n;i++){
    		scanf("%d",&a[i]);
    	}
    	
    	int ans;
    	for(int i=n;i>0;i--){
    		int x=h;
    		
    		for(int j=1;j<=n;j++){
    			b[j]=a[j];
    		}
    		
    		sort(b+1,b+1+i);
    		/*for(int j=1;j<=i;j++){
    			printf("b[%d]=%d\n",j,b[j]);
    		}*/
    		int j;
    		for(j=i;j>0;j-=2){
    			if(b[j]<=x){
    				x-=b[j];
    				//printf("j=%d,x=%d\n",j,x);
    			}else break;
    		}
    		if(j<=0){
    			ans=i;
    			break;	
    		}		
    		
    	}
    	printf("%d\n",ans);
    	return 0;
    }

--------------------

C. Ramesses and Corner Inversion

就这么个题还做不出来，/无奈

#include<bits/stdc++.h>
    using namespace std;
    const int maxn=510;
    int a[maxn][maxn],b[maxn][maxn];
    
    int main(){
    	int n,m;
    	scanf("%d%d",&n,&m);
    	for(int i=0;i<n;i++){
    		for(int j=0;j<m;j++){
    			scanf("%d",&a[i][j]);
    		}
    	}
    	for(int i=0;i<n;i++){
    		for(int j=0;j<m;j++){
    			scanf("%d",&b[i][j]);
    		}
    	}
    	
    	for(int i=0;i<n;i++){
    		for(int j=0;j<m;j++){
    			if(a[i][j]!=b[i][j]){
    				if(i==n-1||j==m-1){
    					printf("No\n");
    					return 0;
    				}
    				b[i][j]^=1;
    				b[i][j+1]^=1;
    				b[i+1][j]^=1;
    				b[i+1][j+1]^=1;
    			}
    		}
    	}
    	printf("Yes\n");
    	
    	return 0;
    }

[http_codeforces.com_contest_1119]: http://codeforces.com/contest/1119
[A. Ilya and a Colorful Walk]: http://codeforces.com/contest/1119/problem/A
[B. Alyona and a Narrow Fridge]: http://codeforces.com/contest/1119/problem/B