分治法求中位数

Posted 2021-01-10 lianggaoblogyuan

别人的参考
https://blog.csdn.net/XDU_PYL/article/details/45967535
自己的算法

include

using namespace std;
void Mid(int a[],int aleft,int aright,int b[],int bleft,int bright)
{
double mid;
int n=aright-aleft+1;
int k1=(aleft+aright)/2;
int k2=(bleft+bright)/2;
if(aright-aleft==1&&bright-bleft==1)
{

    cout<<"mid="<<(max(a[aleft], b[bleft]) + min(a[aright], b[bright])) / 2.0<<endl;
    return ;
}
if((aleft==aright)&&(bleft==bright))
{
    mid=(a[aleft]+b[bleft])/2.0;
    cout<<"mid="<<mid<<endl;
    return;
    
}
else
{
        if(a[k1]==b[k2])
        {
            mid=a[k1];
            cout<<"mid="<<mid<<endl;                
        }

        if(a[k1]<b[k2])
        {
            Mid(a,k1,aright,b,bleft,k2);
            //cout<<"Mid1(a,k1,n-1,b,0,k2)"<<" "<<k1<<" "<<aright<<" "<<" "<<bleft<<" "<<k2<<endl;
        }
        if(a[k1]>b[k2])
        {
            Mid(a,aleft,k1,b,k2,bright);
            //cout<<"Mid2(a,0,k1,b,k2,n-1)"<<" "<<aleft<<" "<<k1-1<<" "<<" "<<k2<<" "<<bright<<endl;
        }
}

}
int main()
{
int a[]={1, 12, 15, 26, 38};
int b[]={13, 14, 40, 42, 45};
Mid(a,0,4,b,0,4);
system("pause");
}