Xianyujunzhu @ 2024-03-30 19:15:09

#include<bits/stdc++.h>
using namespace std;
int main(){
    int n,m,a[105][105];
    cin>>n>>m;
    for(int i=1;i<=m;i++){
        int x1,y1,x2,y2;
        cin>>x1>>y1>>x2>>y2;
        for(int j=x1;j<=x2;j++){
            for(int k=y1;k<=y2;k++){
                a[j][k]++;
            }
        }
    }
    for(int i=1;i<=n;i++){
        for(int j=1;j<=n;i++){
            if(j==n)
                cout<<a[i][j];
            else
                cout<<a[i][j]<<" ";
        }
        cout<<endl;
    }
    return 0;
}

by CTGU_23_sxy @ 2024-03-30 19:17:46

数组开小了，要开到 1005 @Xianyujunzhu

by Xianyujunzhu @ 2024-03-30 19:30:39

@CTGU_23_sxy 还是不行啊

by CTGU_23_sxy @ 2024-03-30 20:27:23

@Xianyujunzhu 会TLE，这要用到二维前缀和的知识

by v11v11blabla @ 2024-04-15 20:24:56

@Xianyujunzhu 见第16行

i++应该为j++

by v11v11blabla @ 2024-04-15 20:26:50

欸您好像过了对不起眼瞎

by wangderui111 @ 2024-05-30 21:00:35

#include<bits/stdc++.h>
using namespace std;
int ans[1005][1005];
int main(){
    int n,m;
    cin>>n>>m;
    for(int i=0;i<m;i++){
        int x1,y1,x2,y2;
        cin>>x1>>y1>>x2>>y2;
        for(int x=x1;x<=x2;x++){
            for(int y=y1;y<=y2;y++){
                ans[x][y]++;
            }
        }
    }for(int x=1;x<=n;x++){
        for(int y=1;y<=n;y++){
            cout<<ans[x][y]<<" ";
        }cout<<endl;
    }return 0;
}

来自萌新的疑问，为什么要用差分

O(mnn)才1000000000（最坏）

by lihaoran2012 @ 2024-07-30 09:58:24

叮~您的代码已改好，请注意签收！

AC代码：```

include<bits/stdc++.h>

using namespace std; int a[1001][1001]; int main(){ int n,m; cin>>n>>m; for(int i=1;i<=m;i++){ int x1,y1,x2,y2; cin>>x1>>y1>>x2>>y2; for(int j=x1;j<=x2;j++){ for(int k=y1;k<=y2;k++){ a[j][k]++; } } } for(int i=1;i<=n;i++){ for(int j=1;j<=n;j++){ if(j==n) cout<<a[i][j]; else cout<<a[i][j]<<" "; } cout<<endl; } return 0; }

by lihaoran2012 @ 2024-07-30 09:59:28

对不起格式写错了

by lihaoran2012 @ 2024-07-30 09:59:47

#include<bits/stdc++.h>
using namespace std;
int a[1001][1001];
int main(){
    int n,m;
    cin>>n>>m;
    for(int i=1;i<=m;i++){
        int x1,y1,x2,y2;
        cin>>x1>>y1>>x2>>y2;
        for(int j=x1;j<=x2;j++){
            for(int k=y1;k<=y2;k++){
                a[j][k]++;
            }
        }
    }
    for(int i=1;i<=n;i++){
        for(int j=1;j<=n;j++){
            if(j==n)
                cout<<a[i][j];
            else
                cout<<a[i][j]<<" ";
        }
        cout<<endl;
    }
    return 0;
}

by lihaoran2012 @ 2024-07-30 10:04:28

数组最好在外面开，而且还要开大一点。然后就能解决超时的问题。要把你第五个循环的i++改成j++就能AC了。