Introduction

I have used CodeBlocks compiler for debugging purpose. But you can use any C++ programming language compiler as per your availability.

#include <iostream>
using namespace std;
 
int main()
{
    int i, num, sum=0;
 
   //Reading number
    cout<<"Enter any number: "<<endl;
    cin>>num;
 
     for(i=1; i<=num; i+=2)
     {
        //Adding current even number to sum variable
        sum += i;
     }
     cout<<"Sum of all odd number between 1 to " << num << ": "<<sum;
 
    return 0;
}

Result