## 题目描述：

Maxsum

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.

Input

The first line of the input contains an integer T(1<=T<=20) which means the number of test cases. Then T lines follow, each line starts with a number N(1<=N<=100000), then N integers followed(all the integers are between -1000 and 1000).

Output

For each test case, you should output two lines. The first line is “Case #:”, # means the number of the test case. The second line contains three integers, the Max Sum in the sequence, the start position of the sub-sequence, the end position of the sub-sequence. If there are more than one result, output the first one. Output a blank line between two cases.

Sample Input

2

5

6 -1 5 4 -7

7

0 6 -1 1 -6 7 -5

Sample Output

Case 1:

14 1 4

Case 2:
7 1 6

## 代码：

#include<stdio.h>
#include<iostream>
using namespace std;
int arr[100010];
int main(){
int t,cnt=0;
cin>>t;
while(t--){
int n,s_id=0,e_id=0,sum=0,summax=-10000,k=1;
scanf("%d",&n);
for(int i=1;i<=n;i++){
scanf("%d",&arr[i]);
}
for(int i=1;i<=n;i++){
sum+=arr[i];
if(sum>summax){
summax=sum;
s_id=k;
e_id=i;
}
if(sum<0){
sum=0;
k=i+1;
}
}
printf("Case %d:\n%d %d %d\n",++cnt,summax,s_id,e_id);
if(t!=0) printf("\n");
}
}


## 代码：

#include <iostream>
#include <stdio.h>
#include <string.h>
#include <string>
#include <stdlib.h>
#include <vector>
#include <algorithm>
#include <math.h>
using namespace std;
const int MAXN=50050;
int n,ans=-2147483647,dp[MAXN],a[MAXN]；
int main()
{
scanf("%d",&n);
for (int i=1;i<=n;i++)
{
scanf("%d",&a[i]);
dp[i]=max(dp[i-1]+a[i],a[i]); //关键
ans=max(ans,dp[i]);
}
printf("%d\n",ans);
return 0;
}