HDU 1003 Max Sum——dp求最大连续和O(n)

sum[i] = max{sum[i - 1] + a[i], a[i]};

ans = max{ans, sum};

注意left和right值应该在更新ans时更新

#include <cstdio>#include <cstring>#include <iostream>#include <algorithm>using namespace std;const int INF = 0x3f3f3f3f;int main(){    int T, n, a, flag = 0; scanf("%d", &T);    while (T--) {        scanf("%d", &n);        int left = 1, right = 1, pos = 1, sum = 0, ans = -INF;        for (int i = 1; i <= n; i++) {            scanf("%d", &a);            sum += a;            if (sum > ans) {                ans = sum;                left = pos;                right = i;            }            if (sum < 0) {                sum = 0;                pos = i + 1;            }        }        if (flag++) printf("\n");        printf("Case %d:\n%d %d %d\n", flag, ans, left, right);    }}