7) Reverse Number
We can reverse a number in c++ using loop and arithmetic operators. In this program, we are getting number as input from the user and reversing that number.
Write a c++ program to reverse given number.
Input: 123
Output: 321
Let's see a simple c++ example to reverse a given number.
#include <iostream>
using namespace std;
int main()
{
int n, reverse=0, rem;
cout<<"Enter a number: ";
cin>>n;
while(n!=0)
{
rem=n%10;
reverse=reverse*10+rem;
n/=10;
}
cout<<"Reversed Number: "<<reverse<<endl;
return 0;
}
8) Swap two numbers without using third variable
We can swap two numbers without using third variable. There are two common ways to swap two numbers without using third variable:
-
By + and -
-
By * and /
Write a c++ program to swap two numbers without using third variable.
Input: a=10 b=20
Output: a=20 b=10
Program 1: Using + and -
Let's see a simple c++ example to swap two numbers without using third variable.
#include <iostream>
using namespace std;
int main()
{
int a=5, b=10;
cout<<"Before swap a= "<<a<<" b= "<<b<<endl;
a=a*b; //a=50 (5*10)
b=a/b; //b=5 (50/10)
a=a/b; //a=10 (50/5)
cout<<"After swap a= "<<a<<" b= "<<b<<endl;
return 0;
}