POJ 1050 动态规划

#include <cstdio>#include <iostream>#include <algorithm>#include <queue>#include <stack>#include <climits>#include <cstring>#include <cmath>#include <map>#include <set>using namespace std;int n;int a[105][105];int dp[105][105];int sum[105][105];int main(){while(scanf("%d",&n)!=EOF){for(int i = 1;i <= n;i++){for(int j = 1;j <= n;j++){scanf("%d",&a[i][j]);}}memset(dp,0,sizeof(dp));for(int j = 1;j <= n;j++){ //j列的和 for(int i = 1;i <= n;i++){sum[j][i] = sum[j][i-1] + a[i][j];}}for(int i = 1;i <= n;i++){for(int j = i;j <= n;j++){int right = 0;for(int k = 1;k <= n;k++){ if(right >= 0){ right += sum[k][j] - sum[k][i-1];  } else{ right = sum[k][j] - sum[k][i-1];  }  dp[i][j] = max(dp[i][j],right); } }}int ans = -INT_MAX;for(int i = 1;i <= n;i++){for(int j = i;j <= n;j++){if(dp[i][j] > ans){ans = dp[i][j];}}}cout << ans << endl;}return 0;}