剑指Offer：连续子数组的最大和

#include <stdio.h>

int maxsum_subarray(int a[], int n)
{
    if( a==NULL || n<=0 )
    {
        printf("Error.\n");
        return 0x80000000;
    }

    int i;
    int curmax = 0x80000000;
    int cursum = 0;
    for( i=0; i<n; i++ )
    {
        if( cursum <= 0 ) // 当前元素之前的若干个元素之和已经<=0; 以当前元素为起点, 继续往后求子数组的和
            cursum = a[i];
        else
            cursum += a[i];

        if( cursum > curmax ) // 更新新的最大值
            curmax = cursum;
    }
    return curmax;
}

int main(void)
{
    int a[] = {19,-20,3,10,-4,7,2,-5};
    int result = maxsum_subarray(a,8);
    printf("%d\n", result);

    return 0;
}