循环交换三个数字

给定三个数字，以循环形式交换它们。第一个数字应该得到第三个的值，第二个应该得到第一个的值，第三个应该得到第二个的值。

例子：

Input : a = 2, b = 4, c = 7
Output : a = 7, b = 2, c = 4

Input : a = 10, b = 20, c = 30
Output : a = 30, b = 10, c = 20

先决条件：指针，引用调用，

这个想法是扩展简单的两个变量交换。

// Before overwriting b, store its 
    // value in temp.
    temp = b;

    // Now do required swapping starting
    // with b.
    b = a;
    a = c;
    c = temp;

C++

// C program to perform Cyclic Swapping
// using Call by Reference
#include 
  
void cyclicSwap(int* a, int* b, int* c)
{
    // Before overwriting b, store its 
    // value in temp.
    int temp = *b;
  
    // Now do required swapping starting
    // with b.
    *b = *a;
    *a = *c;
    *c = temp;
}
  
int main()
{
    int a = 2, b = 4, c = 7;
  
    printf("Value before swapping:\n");
    printf("a = %d \nb = %d \nc = %d\n", a, b, c);
  
    cyclicSwap(&a, &b, &c);
  
    printf("Value after swapping:\n");
    printf("a = %d \nb = %d \nc = %d", a, b, c);
  
    return 0;
}

C#

// C# program to perform Cyclic Swapping
// using Call by Reference
using System;
class GFG {
      
    static void cyclicSwap(ref int a, 
                   ref int b, ref int c)
    {
          
        // Before overwriting b, store 
        // its value in temp.
        int temp = b;
      
        // Now do required swapping 
        // starting with b.
        b = a;
        a = c;
        c = temp;
    }
      
    // Driver code
    public static void Main()
    {
        int a = 2, b = 4, c = 7;
  
        Console.Write("Value before swapping:\n");
        Console.Write("a = " + a + "\n"+ "b = " + 
                    b + "\n" + "c = " + c + "\n");
          
        cyclicSwap(ref a, ref b, ref c);
      
        Console.Write("Value after swapping:\n");
        Console.Write("a = " + a + "\n"+ "b = " +
                   b + "\n" + "c = " + c + "\n");
    } 
}
  
// This code is contributed by Sam007.

输出：

Value before swapping:
a = 2 
b = 4 
c = 7
Value after swapping:
a = 7 
b = 2 
c = 4