结对开发首尾相接数组求子数组最大和

#include<iostream.h>
#include<stdlib.h>
struct ret
{
    int max,start,end;       //用于存放最大值，及始末位置
};

struct ret max2(int arry[],int length)  //跨越arry[n-1]、arry[0]的最大和
{
    int total=0;
    int start1=0;
    int start2;    //起始位置
    int end=0;
    int sum=arry[0];
    int minsum=arry[0];
    for(int i=1;i<length;i++)
    {
        if(sum>0)
        {
            sum=arry[i];
            start1=i;
        }
        else
        {
            sum=sum+arry[i];

        }
        if(minsum>=sum)
        {
            minsum=sum;
            end=i;
            start2=start1;
        }
        total=total+arry[i];
    }
    total=total+arry[0];
    minsum=total-minsum;
    struct ret ret1={minsum,start2,end};
    return ret1;
}


struct ret max1(int arry[],int length)   //不跨越零点的最大和
{
    int start1=0;
    int start2;     //起始位置
    int end=0;
    int sum=arry[0];
    int maxsum=arry[0];
    for(int i=1;i<length;i++)    //求出相邻数组最小和
    {
        if(sum<0)
        {
            sum=arry[i];
            start1=i;
        }
        else
        {
            sum=sum+arry[i];

        }
        if(maxsum<=sum)
        {
            start2=start1;
            end=i;
            maxsum=sum;
        }
    }
    struct ret ret1={maxsum,start2,end};
    return ret1;
}

int main()
{
    srand((unsigned)time(0));
    int N;
    cout<<"输入元素个数:";
    cin>>N;
    int a[20];
    for(int i=0;i<N;i++)
    {
        a[i]=rand()%20-10;
        cout<<a[i]<<"  ";
    }
    cout<<endl;
    struct ret w=max2(a,N);   //调用max2函数，求跨越零点的最值
    struct ret q=max1(a,N);
    if(w.max>q.max)
    {
        cout<<"最大和为:"<<w.max<<"起始位置:"<<w.end+1<<"结束位置:"<<w.start-1;
    }
    else
    {
        cout<<"最大和为:"<<q.max<<"起始位置:"<<q.start<<"结束位置:"<<q.end;
    }
    return 0;
}