LightOJ 1433 - Minimum Arc Distance

题目链接：​​http://www.lightoj.com/volume_showproblem.php?problem=1433​​

题意：给你圆心坐标及圆上的两点坐标，求两点距离。
求对应的圆心角度再求距离。水~

代码：

#include <iostream>
#include <stdio.h>
#include <cmath>
#include <string>
#include <string.h>

using namespace std;

int main()
{
    double x0, y0, x1, y1, x2, y2;
    int t, cases1 = 1;
    scanf("%d", &t);
    while (t--)
    {
        scanf("%lf%lf%lf%lf%lf%lf", &x0, &y0, &x1, &y1, &x2, &y2);
        printf("Case %d: ", cases1++);
        double dis1 = sqrt((x1 - x0)*(x1 - x0) + (y1 - y0)*(y1 - y0));
        double dis2 = sqrt((x1 - x2)*(x1 - x2) + (y1 - y2)*(y1 - y2));

        double tmp = asinf(dis2*1.0 / 2 / dis1);

        double l = 2.0 *dis1;

        double ans = (tmp) * l;
        printf("%.6lf\n",ans);
    }
    return 0;
}