HDU 1003 Max Sum （dp）

Posted 2021-01-30 cake-lover-77

Problem Description

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

 

 1 #include<stdio.h>
 2 #include<string.h>
 3 #include<algorithm>
 4 using namespace std;
 5 int main(){
 6     int t,n,a[100010],cnt=1,dp[100010];
 7     scanf("%d",&t);
 8     int q=t;
 9     while(t--){
10         scanf("%d",&n);
11         memset(dp,0,sizeof(dp));
12         for(int i=1;i<=n;i++){
13             scanf("%d",&a[i]);
14             dp[i]=a[i];
15         }
16         int maxx=dp[1];
17         int t=1;
18         for(int i=1;i<=n;i++){
19             dp[i]=max(dp[i],dp[i-1]+a[i]);
20             if(dp[i]>maxx){
21                 maxx=dp[i];
22                 t=i; //记录最长子序列的末位置 
23             }
24         }
25         int sum=0,tt;
26         for(int i=t;i>=1;i--){
27             sum+=a[i];
28             if(sum==maxx){ //找最长子序列的初始位置 
29                 tt=i;
30             }
31         }
32         printf("Case %d:
",cnt++);
33         printf("%d %d %d
",maxx,tt,t);
34         if(q!=(cnt-1))
35             printf("
");
36     }
37 }