使用临时变量交换数字
#include
int main() {
double first, second, temp;
printf("Enter first number: ");
scanf("%lf", &first);
printf("Enter second number: ");
scanf("%lf", &second);
// Value of first is assigned to temp
temp = first;
// Value of second is assigned to first
first = second;
// Value of temp (initial value of first) is assigned to second
second = temp;
printf("\nAfter swapping, firstNumber = %.2lf\n", first);
printf("After swapping, secondNumber = %.2lf", second);
return 0;
}
输出
Enter first number: 1.20
Enter second number: 2.45
After swapping, firstNumber = 2.45
After swapping, secondNumber = 1.20
在上面的程序中，为temp变量分配了第一个变量的值。
然后，将第一个变量的值分配给第二个变量。
最后，将temp (保留first的初始值)分配给second 。这样就完成了交换过程。
交换数字而不使用临时变量
#include
int main() {
double a, b;
printf("Enter a: ");
scanf("%lf", &a);
printf("Enter b: ");
scanf("%lf", &b);
// Swapping
// a = (initial_a - initial_b)
a = a - b;
// b = (initial_a - initial_b) + initial_b = initial_a
b = a + b;
// a = initial_a - (initial_a - initial_b) = initial_b
a = b - a;
printf("After swapping, a = %.2lf\n", a);
printf("After swapping, b = %.2lf", b);
return 0;
}
输出
Enter a: 10.25
Enter b: -12.5
After swapping, a = -12.50
After swapping, b = 10.25