Max Sum

A - Max Sum
Time Limit:1000MS Memory Limit:32768KB 64bit IO Format:%I64d & %I64u

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Status

Practice

HDU 1003

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

这道题是看的网上的代码敲的，之后不知怎么wa，之后找到了，在代码上看吧：

#include<iostream>#include<cstring>using namespace std;const int maxn=100000+1;int  main(){    int t;    cin>>t;    int a[maxn];    int d[maxn];    int k=1;    int n;    while(t--)    {        memset(d,0,sizeof(d));        cin>>n;        for(int i=1;i<=n;i++)            cin>>a[i];        d[1]=a[1];        for(int i=2;i<=n;i++)        {            if(d[i-1]<0)d[i]=a[i];            else d[i]=d[i-1]+a[i];        }        int max1=d[1];        int end1=1;        for(int i=2;i<=n;i++)        {            if(d[i]>max1)//开始的时候是d[i]写成a[i]了，原来的endl也没有赋值，使得后面的endl在循环中也没有杯赋值，所以程序开始的时候老意外终止。            {                max1=d[i];                end1=i;            }        }        int sum=0;        int start=end1;////        cout<<"Case "<<k++<<":"<<endl;//        cout<<max1<<" "<<start<<" "<<end1<<endl;        for(int i=end1;i>=1;i--)        {           sum+=a[i];           if(sum==max1)                {                    start=i;                }        }        cout<<"Case "<<k++<<":"<<endl;        cout<<max1<<" "<<start<<" "<<end1<<endl;        if(t)            cout<<endl;    }    return 0;}//后面改完了这个问题之后，提交上去就是wa，后面自己测试了一下，如  3 -1 -2 -3 结果是-1 3 3 ，后面我想了一下，原来是当初endl定义的时候赋值是n，后面改成1之后就ac了