so easy 直接上答案

#include <stdio.h>
int main()
{
    long long n=0,max,prev,cur;
    scanf("%lld",&n);
    scanf("%lld",&prev);
    max = prev;
    for(long long i=1;i<n;++i)
    {
        scanf("%lld",&cur);
        prev = cur>(prev+cur)?cur:(prev+cur);
        max = max > prev ? max : prev;
    }
    printf("%lld",max);
    return 0;
}