关于求最大子列和并输出前后两端问题

Question

#include <iostream>
using namespace std;
void maxsum(int p[],int numb){
int i,j,front,back;
int ThisSum,MaxSum1;
ThisSum=MaxSum1=0;
for(i=0,j=p[i];i<numb;i++){
ThisSum+=p[i];
if(ThisSum>MaxSum1){
MaxSum1=ThisSum;
front=j;
back=p[i];
}else if(ThisSum<0){
    ThisSum=0;
    j=p[i+1];
}
}
cout<<MaxSum1<<" "<<front<<" "<<back;
}
int main(){
int num;
cin>>num;
int *p=new int[num];
int number=num;
while(num){
cin>>p[num-1];
num--;
}
maxsum(p,number);
delete p;
return 0;
}

10
-10 1 2 3 4 -5 -23 3 7 -21输入
预期结果10 1 4
代码实际结果10 7 3
这样记录前后两端数字有什么问题

Answer 1

希望采纳

```c++
#include<iostream>
#include<algorithm>
using namespace std;
const int N=1e5+10;
int dp[N],bg[N],idx;
int main()
{
    int n;
    cin>>n;
    for(int i=1;i<=n;i++)
    cin>>dp[i];
    int maxx=-1e9;
    for(int i=1;i<=n;i++)
    {
        if(dp[i-1]>0)
        {
            dp[i]=dp[i-1]+dp[i];
            bg[i]=bg[i-1];
        }
        else
        {
            bg[i]=i;
        }
        if(maxx<dp[i])
        {
            maxx=dp[i];
            idx=i;
        }
//        cout<<dp[i]<<endl;
    }
    cout<<dp[idx]<<" "<<bg[idx]-1<<" "<<idx-1<<endl;
    return 0;
}
/*
10
-10 1 2 3 4 -5 -23 3 7 -21
*/

```