Question

c++怎么用引用变量交换两个整数的数值

Answer 1

//--------------------------------
// 环境：VS2005 // 用途：不用中间变量交换两个数 // 时间：2010.9.25 // 作者：http://pppboy.blog.163.com //-------------------------------- #include "stdafx.h" #include <iostream> using namespace std; //交换a，b void fSwap1(int& a, int& b) { a = a ^ b; b = a ^ b; a = a ^ b; } //交换a，b的另一种方法 void fSwap2(int& a, int& b) { a = a + b; b = a - b; a = a - b; } //再一种方法 void fSwap3(int& a, int& b) { a = a * b; b = a / b; a = a / b; } int main(int argc, char* argv[]) { int a, b; cout << "------------------------------" << endl; cout << "input a :" << endl; cin >> a; cout << "input b :" << endl; cin >> b; cout << "------------------------------" << endl; cout << "a = " << a << endl; cout << "b = " << b << endl; cout << "------------------------------" << endl; fSwap1(a, b); cout << "after swap (1):" << endl; cout << "a = " << a << endl; cout << "b = " << b << endl; fSwap2(a, b); cout << "after swap (2):" << endl; cout << "a = " << a << endl; cout << "b = " << b << endl; fSwap3(a, b); cout << "after swap (3):" << endl; cout << "a = " << a << endl; cout << "b = " << b << endl; system("pause"); return 0; }
结果为： ------------------------------ input a : 32 input b : 65 ------------------------------ a = 32 b = 65 ------------------------------ after swap (1): a = 65 b = 32 after swap (2): a = 32 b = 65 after swap (3): a = 65 b = 32 请按任意键继续. . .当然，第一个还是最好，因为它不担心a，b数字大时越界的问题。

Answer 2

int swapf(int& a, int& b)
{
int temp = a;
a = b;
b = temp;
}

Answer 3

#define swab(a, b) (a ^= b ^= a ^= b)