# Reverse Integer

  • Given an integer and we have to reverse that integer.

  • Eg num = 1234 on reversing num = 4321

# Source Code - C++

#include <iostream>
using namespace std;

//Function to Reverse Integer
int Reverse (int num)
{
 int flag=0, r=0;

 //flag to check if number is negative
 if(num<0)
 flag=1;

 //Taking absolute value of number
 num=abs(num);

 //Reversing number digit by digit
 while(num>0)
 {
  r=r*10+num%10;
  num=num/10;
 }

 //if falg set make number negative
 if(flag==1)
 r=r*(-1);
 return r;
}
//Main Function
int main() {

 int num;
 cout<<"Enter number to be reversed\n";
 cin>>num;
 num=Reverse(num);
 cout<<"Reversed number is:"<<num;
 return 0;
}

Time Complexity : O(n)

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  • Reverse Integer