本文实例演示了C语言求幂计算的高效解法。很有实用价值。分享给大家供大家参考。具体方法如下：
题目如下：
给定base，求base的幂exp
只考虑基本功能，不做任何边界条件的判定，可以得到如下代码：
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#include <iostream>using namespace std;int cacExp(int base, int exp){ int result = 1; int theBase = 1; while (exp) { if (exp & 0x01) result = result * base; base = base * base; exp = exp >> 1; } return result;}int getRecurExp(int base, int exp){ if (exp == 0) { return 1; } if (exp == 1) { return base; } int result = getRecurExp(base, exp >> 1); result *= result; if (exp & 0x01) result *= base; return result;}int main(){ for (int i = 1; i < 10; i++) { int result = cacExp(2, i); //int result = getRecurExp(2, i); cout << "result: " << result << endl; } return 0;} |
再来看看数值的整数次方求解方法：
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#include <iostream>using namespace std;bool equalZero(double number){ if (number < 0.000001 && number > -0.000001) return true; else return false;}double _myPow(double base, int exp){ if (exp == 0) return 1; if (exp == 1) return base; double result = _myPow(base, exp >> 1); result *= result; if (exp & 0x01) result *= base; return result;}double _myPow2(double base, int exp){ if (exp == 0) return 1; double result = 1; while (exp) { if (exp & 0x01) result *= base; base *= base; exp = exp >> 1; } return result;}double myPow(double base, int exp){ if (equalZero(base)) return 0; if (exp == 0) return 1; bool flag = false; if (exp < 0) { flag = true; exp = -exp; } double result = _myPow2(base, exp); if (flag) { result = 1 / result; } return result;}void main(){ double base = 2.0; int exp = -5; double result = myPow(base, exp); cout << "result: " << result << endl;} |
相信本文所述对大家C程序算法设计的学习有一定的借鉴价值。
