1. Swap two numbers in C. #include<stdio.h> int main() { int a, b; scanf("%d%d", &a, &b); int temp; temp = *x; *x = *y; *y = temp; printf("%d %d", a, b); return 0; } 2. Swap two numbers in C using recursion method. #include<stdio.h> void swap(int *x, int *y) { int temp; temp = *x; *x = *y; *y = temp; } int main() { int a, b; scanf("%d%d", &a, &b); swap(&a, &b); printf("%d %d", a, b); return 0; } 3. Swap two numbers in C without using any other variable. #include<stdio.h> int main() { int a, b; scanf("%d%d", &a, &b); a = a ^ b; b = a ^ b; a = a ^ b; printf("%d and %d", a, b); return 0; }