曼哈顿距离

d(i,j)=|X1-X2|+|Y1-Y2|

欧式距离

直线距离

#include<iostream>
#include<cmath>
using namespace std;
int main()
{
    int n;
    cin>>n;
    int x=n/2,y=n/2;
    for(int i=0;i<n;i++)
    {
        for(int j=0;j<n;j++)
        {
            if(abs(x-i)+abs(y-j)<=n/2)
                cout<<"*";
            else
                cout<<" ";
        }
        cout<<endl;
    }
    return 0;
}