FZU 2140 Forever 0.5（将圆离散化）

  主要就是将圆离散化,剩下的都好办

#include<iostream>
#include<cstdio>
#include<cstring>
#include<cmath>
using namespace std;
#define add 0.005
double x[150],y[150];
int main()
{
    int t,n;
    scanf("%d",&t);
    x[0] = y[0] = 0;
    x[1] = 1,y[1] = 0;
    x[2] = 0.5,y[2] = sqrt(0.75);
    x[3] = 0.5,y[3] = y[2]-1;
    for(int i = 4;i <= 100;i++)
    {
        x[i] = 0.5 + (i-3) * add;
        y[i] = sqrt(1 - x[i]*x[i]);
    }
    while(t--)
    {
        scanf("%d",&n);
        if(n <= 3)
        {
            puts("No");
            continue;
        }
        puts("Yes");
        for(int i = 0;i < n;i++)
        {
            printf("%.6lf %.6lf
",x[i],y[i]);
        }
    }
}