浮点数平方根，立方根 c++

Posted 2022-11-24 每天告诉自己要努力

//平方根
#include <iostream>
#include <algorithm>
using namespace std;

int main() 
	double n = 1e-5; //小数点5位
	double target = 0.9; //要算平方根的数
	double l = 0; //左边界
	double r = max(1.0, target); //右边界，必须大于1
	while (r - l > n) 
		double mid = (r + l) / 2;
		if (mid * mid >= target) r = mid;
		else l = mid;
	
	cout << l << endl;
	return 0;

//立方根
#include <iostream>
#include <algorithm>
using namespace std;

int main() 
	double n = 1e-5; //误差
	double target = 10; //目标数
	double l = -10000;//上边界
	double r = 10000;//下边界
	while (r - l > n) 
		double mid = (r + l) / 2;
		if (mid * mid * mid >= target) r = mid;
		else l = mid;
	
	cout << l << endl;
	return 0;