POJ 1157 LITTLE SHOP OF FLOWERS 水DP

注意边界

#include<stdio.h>
#include<string.h>
#include<algorithm>
using namespace std;
#define inf 1000000000
int max(int a, int b) {return a > b ? a : b;}
int n, m;
int a[103][103], dp[103][103];
int main()
{
    int i, j;
    while( ~scanf("%d%d", &n, &m))
    {
        for(i = 1; i <= n; i++)
            for(j = 1; j <= m; j++)
                scanf("%d", &a[i][j]);
        for(i = 0; i <= m; i++) dp[0][i] = 0;
        for(i = 1; i <= n; i++) dp[i][0] = -inf;
        for(i = 1; i <= n; i++)
            for(j = 1; j <= m; j++)
                dp[i][j] = max(dp[i-1][j-1] + a[i][j], dp[i][j-1]);
        printf("%d\n", dp[n][m]);
    }
    return 0;
}