max sum 不用考虑全是负数。。

#include <stdio.h>
#include <string.h>
#include <stdlib.h>

int dp[100010];

int main( )
{
    int T, i, j, N, a, b, c, d, l, max, sum, flag ;
    scanf("%d",&T);
    l = 0;

    while (T--) {
        l++;
       
        //sum = max = 0;
        memset(dp, 0, sizeof(dp));
        scanf("%d",&N);
        for (i = 1; i <= N; i++)
            scanf("%d",&dp[i]);
     
     
        
        printf("Case %d:\n",l);
        
        max = sum = dp[1];
        a = b = c = d = 1;
        for (i = 2; i <= N; i++) {
            if (sum < 0)
                sum = dp[i], a = i, b = i;
            else
                sum += dp[i], b = i;
            if (sum > max) {
                c = a;
                d = b;
                max = sum;
            }
        }
        printf("%d %d %d\n",max,c,d);
        if (T)
            puts("");
    }
    return 0;
}