@[tiying](/user/1057689)
第15行算式的最后一项，你把 $y1$ 打成 $y2$ 了。
AC code:
```cpp
#include<stdio.h>
int m[130][130],n,c,t,max = -200;
int main(){
scanf("%d",&n);
for(int i = 1;i<=n;++i){
for(int j = 1;j<=n;++j){
scanf("%d",&c);
m[i][j] = m[i-1][j]+m[i][j-1]-m[i-1][j-1]+c;
}
}
for(int x1 = 1;x1<=n;x1++){
for(int y1 = 1;y1<=n;y1++){
for(int x2 = x1;x2<=n;x2++){
for(int y2 = y1;y2<=n;y2++){
c = m[x2][y2]-m[x1-1][y2]-m[x2][y1-1]+m[x1-1][y1-1];
if(c>max) max = c;
}
}
}
}
printf("%d",max);
return 0;
}
```
by 07kzs @ 2023-08-31 22:01:52
@[07kzs](/user/222609) ......太粗心了，下次得仔细点，谢谢了
by tiying @ 2023-08-31 22:05:58