我有一个c ++算法,可以计算整数的平方根.除了一个缺陷外,该程序可以正常运行.它无法计算低于1的数字的平方根.例如,它无法计算.5或.9或.0000001等的平方根,但在所有其他情况下按计划工作.我有X设置所以它不允许负输入,但我仍然不明白为什么它不会返回任何小于1的值.
include <iostream>
#include <cmath>
#include <cassert>
using namespace std;
double squareroot(double x)
{ /* computes the square root of x */
/* make sure x is not negative .. no math crimes allowed! */
assert(x >= 0);
if (x == 0) return 0;
/* the sqrt must be between xhi and xlo */
double xhi = x;
double xlo = 0;
double guess = x / 2;
/* We stop when guess*guess-x is very small */
while (abs(guess*guess - x) > 0.000001)
{
if (guess*guess > x) xhi = guess;
else xlo = guess;
guess = (xhi + xlo) / 2;
}
return guess;
}
/* Test Stub */
int main()
{
double testvalue;
cout << "\n Enter a TestValue= ";
cin >> testvalue;
cout << endl;
double testresult = squareroot(testvalue);
cout << "\n Square Root= " << testresult << "\n";
}
谢谢您的帮助!我能够通过使用以下方法解决问题:
if (x<1) {
xhi = 1;
xlo = x;
guess = (x + 1) / 2;
}