HDU 1231 最大连续子序列

http://acm.hdu.edu.cn/showproblem.php?pid=1231

Dp[i] 以a[i]元素结尾的子序列的最大和

记录 再记录一下起始位置即可

#include <iostream>
#include <string.h>
#include <stdio.h>
using namespace std;

int a[10007];
int dp[10007];
int st[10007];
int main()
{
    int n;
    while(cin >> n)
    {
        bool neg = true;
        if (!n) break;
        memset(dp, 0 ,sizeof(dp));
        for (int i = 0; i < n; i++)
        {
            scanf("%d", &a[i]);
            if (a[i] >= 0) neg = false;
        }
        if (neg)
        {
            cout << 0 << " " << a[0] << " " << a[n-1] << endl;
            continue;
        }
        dp[0] = a[0];
        st[0] = 0;
        for (int i = 1; i < n; i++)
        {
            if (dp[i-1]+a[i] > a[i])
            {
                dp[i] = dp[i-1]+a[i];
                st[i] = st[i-1];
            }
            else
            {
                dp[i] = a[i];
                st[i] = i;
            }
        }
        int ans = -1e9;
        int index = 0;
        for (int i = 0; i < n; i++)
        {
            if(ans < dp[i])
            {
                index = i;
                ans = dp[i];
            }
        }
        cout << ans << " " << a[st[index]] << " " << a[index] << endl;
    }
    return 0;
}