不使用临时变量完成变量交换

加减，乘除，异或

#include <stdio.h>

void fun1(int a, int b) {
    printf("%d, %d	", a, b);
    // a = a + b - (b = a);
    a += b;
    b = a - b;
    a = a - b;
    printf("%d, %d
", a, b);
}

void fun2(int a, int b) {
    printf("%d, %d	", a, b);
    // a = a * b / (b = a);
    a *= b;
    b = a / b;
    a = a / b;
    printf("%d, %d
", a, b);
}

void fun3(int a, int b) {
    printf("%d, %d	", a, b);
    // b ^= a ^= b ^= a;
    a ^= b; // 0^0=0    0^1=1   ^异或：不同的为 1
    b = a ^ b;
    a = a ^ b;
    printf("%d, %d
", a, b);
}

int main() {
    int a = 3, b = 4;
    fun1(a, b);
    fun2(a, b);
    fun3(a, b);
    printf("%d, %d	", a, b);
}

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https://blog.csdn.net/u011433274/article/details/15786797