Programming
Consider we have two variables x and y containing some number. We are asked to swap the values without using a third variable. To solve this problem we follow the given steps (algorithm)
x = x + y y = x - y x = x - y
Let x = 10 and y = 20 So, x = x + y = 10 + 20 = 30 y = x - y = 30 - 20 = 10 x = x - y = 30 - 10 = 20
Let x = 10 and y = -20 So, x = x + y = 10 + (-20) = -10 y = x - y = (-10) - (-20) = (-10) + 20 = 10 x = x - y = (-10) - 10 = -20
Let x = -10 and y = -20 So, x = x + y = (-10) + (-20) = -30 y = x - y = (-30) - (-20) = (-30) + 20 = -10 x = x - y = (-30) - (-10) = (-30) + 10 = -20
#include <stdio.h> int main(){ //variables int x, y; //input printf("Enter value of x and y: "); scanf("%d%d", &x, &y); //swap x = x + y; y = x - y; x = x - y; //output printf("x = %d y = %d\n", x, y); return 0; }