方法1:通过加减法运算来交换,缺点是当两个数值的和超出了数据类型的存储范围时会发生溢出
1 #include <stdio.h> 2 int main(){ 3 int a = 10,b = 20; 4 printf("交换前:\na = %d,b = %d",a,b); 5 a = a + b;//将a,b的和存放在a中,b的值没有改变 6 b = a - b;//a - b的值即a原本的值,赋值给b,此时b中存放的a的值 7 a = a - b;//再将a - b的值赋给a,此时a中存放的就是原本b中的值 8 printf("交换后:\na = %d,b = %d",a,b); 9 }
方法2:通过乘除法运算来交换,缺点同上
1 #include <stdio.h> 2 int main(){ 3 int a = 10,b = 20; 4 printf("交换前:\na = %d,b = %d",a,b); 5 a = a * b;//将a,b的乘积存放在a中,b的值没有改变 6 b = a / b;//a / b的值即a原本的值,赋值给b,此时b中存放的a的值 7 a = a / b;//再将a / b的值赋给a,此时a中存放的就是原本b中的值 8 printf("交换后:\na = %d,b = %d",a,b); 9 }
方法3:通过异或运算来交换,异或运算不会造成数据溢出,位运算满足交换律和结合律,异或运算有自反性质
自反性:a ^ b ^ b = a
1 #include <stdio.h> 2 int main(){ 3 printf("交换前:\na = %d,b = %d",a,b); 4 int a = 10,b = 20; 5 a = a ^ b;//a中存放的是0001 1110
a = 0000 1010
b = 0001 0100
a^b=0001 1110
6 b = a ^ b;//b中存放的是0000 1010,即存放a
因为a = a ^ b
所以b = a ^ b = a ^ b ^ b = a ^ (b ^ b) = a
7 a = a ^ b;//a = b
因为a = a ^ b,b = a ^ b = a ^ b ^ b
所以a = a ^ b = a ^ b ^ a ^ b ^ b = a ^ b ^ a = b
8 printf("交换后:\na = %d,b = %d",a,b); 9 }
标签:变量,int,na,变量值,printf,交换,存放,借用,运算 From: https://www.cnblogs.com/izxw/p/18392065