//注释掉函数调用时没问题的，加了就有问题
//有空帮看看，谢谢
#include<iostream>
using namespace std;

void choose(int a[],int n)
{
    if(n<=6 && n>=3)
    {
        switch (n)
        {
        case 3:
            {
                int i,j,k;
                for(i=0;i<10;i++)
                    for(j=i+1;j<10;j++)
                        for(k=j+1;k<10;k++)
                        {
                            if((a[i]+a[j]+a[k])>=45 && (a[i]+a[j]+a[k])<=90)
                                cout<<"a[i]-a[j]-a[k]"<<a[i]<<a[j]<<a[k]<<endl;
                        }
            }
        case 4:
            {
                int i,j,k,m;
                for(i=0;i<10;i++)
                    for(j=i+1;j<10;j++)
                        for(k=j+1;k<10;k++)
                            for(m=k+1;m<10;m++)
                            {
                                if((a[i]+a[j]+a[k]+a[m])>=45 && (a[i]+a[j]+a[k]+a[m])<=90)
                                    cout<<"a[i]-a[j]-a[k]-a[m]"<<a[i]<<a[j]<<a[k]<<a[m]<<endl;
                            }
            }
        case 5:
            {
                int i,j,k,m,n;
                for(i=0;i<10;i++)
                    for(j=i+1;j<10;j++)
                        for(k=j+1;k<10;k++)
                            for(m=k+1;m<10;m++)
                                for(n=m+1;n<10;i++)
                                {
                                    if((a[i]+a[j]+a[k]+a[m]+a[n])>=45 && (a[i]+a[j]+a[k]+a[m]+a[n])<=90)
                                    cout<<"a[i]-a[j]-a[k]-a[m]-a[n]"<<a[i]<<a[j]<<a[k]<<a[m]<<a[n]<<endl;
                                }
            }
        case 6:
            {    
                int i,j,k,m,n,t;
                for(i=0;i<10;i++)
                    for(j=i+1;j<10;j++)
                        for(k=j+1;k<10;k++)
                            for(m=k+1;m<10;m++)
                                for(n=m+1;n<10;i++)
                                    for(t=n+1;t<10;t++)
                                {
                                    if((a[i]+a[j]+a[k]+a[m]+a[n]+a[t])>=45 && (a[i]+a[j]+a[k]+a[m]+a[n]+a[t])<=90)
                                    cout<<"a[i]-a[j]-a[k]-a[m]-a[n]-a[t]"<<a[i]<<a[j]<<a[k]<<a[m]<<a[n]<<a[t]<<endl;
                                }
            }
        }
    }
    else
    {
        cout<<"your choose is wrong!"<<endl;
    }
}

void main()
{
    int a[10]={8,13,6,9,7,15,10,5,12,9};
    cout<<"please choose 3:"<<endl;
    choose(int a, 3);
    cout<<"please choose 4:"<<endl;
    choose(int a, 4);
    cout<<"please choose 5:"<<endl;
    choose(int a, 5);
    cout<<"please choose 6:"<<endl;
    choose(int a, 6);
}

在线等急用，谢谢

我的吸引力不大了