hdoj-1003及动态规划理解

　求最大连续子数组之和

Given a sequence a[1],a[2],a[3]......a[n], your job is to calculate the max sum of a sub-sequence. For example, given (6,-1,5,4,-7), the max sum in this sequence is 6 + (-1) + 5 + 4 = 14.

#include <stdio.h>
int main()
{
    int n=0;
    scanf("%d",&n);
    for (int i=1;i<=n;i++)
    {
        int sum=0,begin=0,end=0,temp=1,m=0;
        long max=-100000;
        int a=0;
        scanf("%d",&m);
        for(int j=1;j<=m;j++)
        {
            scanf("%d",&a);
            if(sum>=0)
            {
                sum+=a;
            }
            else
            {
                sum=a;
                temp=j;
            }
            if(sum>max)
            {
                max=sum;
                begin=temp;
                end=j;
            }
        }
        printf("Case %d:
",i);
        printf("%d %d %d
",max,begin,end);
        if (i != n)
            printf("
");
    }
    return 1;
}

该问题类似背包问题，动态规划公式如下：

s[1] = a[1];

s[n] = s[n-1]>=0?s[n-1]+a[n]:a[n];