请各位大神帮小弟我看一上为什么杭电ACM第三题提交后出现Wrong Answer

请各位大神帮我看一下为什么杭电ACM第三题提交后出现Wrong Answer
子序列最大和（杭电acm1003）
分类： ACM 2012-03-25 21:50 34人阅读评论(1) 收藏举报
Max Sum
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

C/C++ code

#include<iostream>
using namespace std;

void maxsubsum(int * num,int length)
{
    int max,sum=0,i,j,start1=0,start2=0,end;
    max=num[0];
    for(i=0;i<length;i++)
    {
        sum+=num[i];
        if(max<sum)
        {
            max=sum;
            start1=start2;
            end=i;
        }
        if(sum<0)
        {
            sum=0;
            start2=i+1;
        }
    
    }
    cout<<max<<" "<<start1+1<<" "<<end+1<<endl;

}
int main()
{
    int casenumber;
    int number;
    int integer;
    cin>>casenumber;
    if(casenumber<1||casenumber>20)
    {
        cout<<"There is something wrong for your input!!";
        exit(0);
    }
    int ** num = new int *[casenumber];
    int * length = new int[casenumber];
    for(int i=0;i<casenumber;i++)
    {
        cin>>number;
        if(number>=1&&number<=100000)
        {
            num[i]=new int[number];
            length[i]=number;
        }
        for(int j=0;j<number;j++)
        {
            cin>>integer;
            if(integer<-1000||integer>1000)
            {
                cout<<"the integer you input is wrong!!";
                continue;
            }
            num[i][j]=integer;
        
        }
        cout<<endl;
    }
    for(int j=0;j<casenumber;j++)
    {
        cout<<"case"<<j+1<<":"<<endl;
        maxsubsum(num[j],length[j]);
        if(j!=casenumber-1)
            cout<<endl;
    }
}

我不知道

------解决方案--------------------
仅仅用一个循环就求出最大子列是不可能的.
例如数列: 6, -1, -7, 4.
你在算出6, -1, -7之后发现sum<0, 马上丢弃另辟新径, 结果得出4为最大子列.
殊不知在丢弃的那一串列中已然包含最大子列, 即6.
可以说, 你的算法是极度贪婪的, 缺不符合贪婪属性.
------解决方案--------------------
这代码风格？。。。。。在oj上做题得悠着点

C/C++ code


#include<iostream>
using namespace std;
const int inf=0x3fffffff;
int MaxSubSeq(const int*arr,int len,int& s,int& e){
    int sum=0,max=-inf,b=0,f=0;
    s=b;
    e=f;
    for(int i=0;i<len;i++){
         sum+=arr[i];
         f=i;
         if(sum>max){
             max=sum;
             s=b;
             e=f;
         }
         if(sum<0){
             sum=0;
             b=i+1;
         }
    }
    return max;
}
int main(){
    int t,len,arr[100005],s,e,max;
    scanf("%d",&t);
    for(int i=1;i<=t;i++){
        scanf("%d",&len);
        for(int j=0;j<len;j++)
             scanf("%d",&arr[j]);
        max=MaxSubSeq(arr,len,s,e);
        if(i>1)
             puts("");
        printf("Case %d:\n",i); 
        printf("%d %d %d\n",max,s+1,e+1);
    }
    return 0;
}

请各位大神帮小弟我看一上为什么杭电ACM第三题提交后出现Wrong Answer

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