Thursday 16 November 2017

How to reverse a number in C++?

Write a C++ program to reverse digits of a number 
Reverse number:-
Input=7890
Output=0987

Algorithm:-
Input=number
reverse_number=0;
while loop number > 0

(a)multiply reverse_number by 10 and add remainder    of number divide by 10 to reverse_number
   reverse_number= reverse_number*10+number%10;

(b)divide number by 10
   number=number/10;

print reverse_number.

Approach to solve:-

Input:num=7890
rev_num=0
rev_num=rev_num*10+num%10=0
num=num/10=789
rev_num=rev_num*10+num%10=09
num=num/10=78
rev_num=rev_num*10+num%10=098
num=num/10=7
rev_num=rev_num*10+num%10=0987
num=num/10=0

Program:-
#include<iostream>
using namespace std;
int main()
{

 int num,rev_num=0;
 cout<<"Enter a number:";
 cin>>num;
 while(num>0)
 {
  rev_num=rev_num*10+num%10;
  num=num/10;
 }
 cout<<rev_num<<endl;


 return 0;
}
Output:-
Enter a number:7890
0987
    HAPPY CODING.......

if any query email me at:-sushank123456@gmail.com




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