hdoj5280最大区间和

//通过sum[0,j] - sum[0,i]，i是前面的最小和

#include <iostream>
using namespace std;
#define MAX_N 1010

typedef long long ll;
ll num[MAX_N];
int main()
{
int T;
int N,P;
cin>>T;
while(T--)
{
cin>>N>>P;
for (int i=0;i<N;++i)
cin>>num[i];

ll ans = -1000000008;
for (int i=0;i<N;++i)
{
ll last = num[i];
num[i] = P;
ll p = 0,s=0;
for (int j=0;j<N;++j)
{
s+=num[j];
ans = max(ans,s-p);
p = min(p,s);//最小的前缀和
}
num[i] = last;
}
cout<<ans<<endl;
}
return 0;
}