Zoj 3806 incircle and circumcircle (two points)

Link: zoj 3806 incircle and circumcircle

Given the inner circle radius and outer circle radius of a triangle, calculate the length of the three sides of the triangle.

Solution: We construct an equi-waist triangle. When determining the outer circle radius, the radius of the incircle is 0? 3 ￣ √ R. You can perform a two-point judgment.

#include <cstdio>#include <cstring>#include <cmath>#include <algorithm>using namespace std;double f (double a, double R) {    double t = sqrt(R * R - a * a / 4) + R;    return sqrt(t * t + a * a / 4);}double judge (double a, double b, double R) {    return a * b * b / (2 * R  * (a + b + b));}double bsearch (double l, double R, double v) {    double r = sqrt(3.0) * R;    for (int i = 0; i < 1000; i++) {        double mid = (l + r) / 2;        double x = f(mid, R);        if (judge(mid, x, R) > v)            r = mid;        else            l = mid;    }    return (l + r) / 2;}int main () {    int r, R;    while (scanf("%d%d", &r, &R) == 2) {        if (r * 2 > R)            printf("NO Solution!\n");        else {            double a = bsearch(0, R, r);            double b = f(a, R);            printf("%.10lf %.10lf %.10lf\n", a, b, b);        }    }    return 0;}

Zoj 3806 incircle and circumcircle (two points)