交换两个变量值的三种写法

    int a = 5;
    int b = 10;
    printf("a== %d,b == %dn",a,b);
    
    int temp = a;
    a = b;
    b = temp;
    printf("a== %d,b == %dn",a,b);

    int a = 5;
    int b = 10;
    printf("a== %d,b == %dn",a,b);
    
    a = a + b ;
    b = a - b;
    a = a - b;
    printf("a== %d,b == %dn",a,b);

    int a = 5;
    int b = 10;
    printf("a== %d,b == %dn",a,b);
    
    a = a ^ b ;
    b = a ^ b;
    a = a ^ b;
    printf("a== %d,b == %dn",a,b);