1. C program to swap two numbers without using third variable
This C program swaps the values of two variables without using a third variable.
Program: Swap the numbers in C
#include<stdio.h> int main() { int a,b; printf("Enter two numbers: "); scanf("%d %d",&a,&b); printf("\nThe values before swapping -> \ta= %d and b= %d",a,b); a=a+b; // a+=b is same as a=a+b b=a-b; a=a-b; printf("\nThe values after swapping -> \ta= %d and b= %d\n",a,b); return 0; }
Sample Output: Swap the values and print them
Enter two numbers: 219 538
The values before swapping -> a= 219 and b= 538
The values after swapping -> a= 538 and b= 219
2. C program to swap two numbers using third variable
This C program swaps the values of variables using a third variable.
Program: Swap two numbers
#include<stdio.h> int main() { int a,b,temp; printf("Enter two numbers: "); scanf("%d %d",&a,&b); printf("\nValues of a and b before swapping ->\t a=%d and b=%d",a,b); temp=a; //store value of a inside the temp variable a=b; //No explanation needed b=temp; //Allocate the stored value of a(original) to b printf("\nValues of a and b after swapping ->\t a=%d and b=%d\n",a,b); return 0; }
Sample Output: Swap numbers and print values
Enter two numbers: 34 67
Values of a and b before swapping -> a=34 and b=67
Values of a and b after swapping -> a=67 and b=34
3. C program to swap two numbers using pointers and functions
This C program takes two numbers as input from the user and then swaps them using a user-defined function.
Program: C program to swap two numbers using function
#include<stdio.h> //function prototype void swap(int *n1, int *n2); int main() { int num1, num2; printf("Enter two numbers(a & b): "); scanf("%d %d", &num1, &num2); printf("Before swapping:\nNumber1= %d\nNumber2= %d\n\n", num1, num2); swap(&num1, &num2); printf("After swapping:\nNumber1= %d\nNumber2= %d\n", num1, num2); return 0; } //function definition void swap(int * n1, int * n2) { int temp; temp = *n1; *n1 = *n2; *n2 = temp; }
Output: print numbers after swapping
Enter two numbers(a & b): 35 92
Before swapping:
Number1= 35
Number2= 92
After swapping:
Number1= 92
Number2= 35
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