Hamming Code

//Hamming code

#include<bits/stdc++.h>
using namespace std;

int main(){
    int a[12];
    cout << "Enter 7 data bits to be transmitted\n";
    for(int i = 11; i > 0; i--){
        if(i!=1 && i!=2 && i!=4 && i!=8){
            cin >> a[i];
        }
    }
    a[1] = (a[3]+a[5]+a[7]+a[9]+a[11])%2;
    a[2] = (a[3]+a[6]+a[7]+a[10]+a[11])%2;
    a[4] = (a[5]+a[6]+a[7])%2;
    a[8] = (a[9]+a[10]+a[11])%2;

    cout << "\nHamming code : ";
    for(int i = 11; i > 0; i--){
        cout << a[i] << " ";
    }
    cout << "\nDo you want to make any error (Y/N) : ";
    char c;
    cin >> c;
    if(c == 'Y'){
        cout << "\nEnter the position to make error : ";
        int pos;
        cin >> pos;
        a[pos] = ((a[pos] == 0)?1:0);
    }
    cout << "\nData Received : ";
    for(int i = 11; i > 0; i--){
        cout << a[i] << " ";
    }
    int r1,r2,r4,r8;
    r1 = (a[1]+a[3]+a[5]+a[7]+a[9]+a[11])%2;
    r2 = (a[2]+a[3]+a[6]+a[7]+a[10]+a[11])%2;
    r4 = (a[4]+a[5]+a[6]+a[7])%2;
    r8 = (a[8]+a[9]+a[10]+a[11])%2;

    int error_position = (r8*8) + (r4*4) + (r2*2) + (r1*1);
    if(error_position){
        cout << "\nError detected at position " << error_position;
        a[error_position] = ((a[error_position] == 0)?1:0);
    }
    else{
        cout << "\nNo error occured\n";
    }
    cout << "\nFinal Data : ";
    for(int i = 11; i > 0; i--){
        cout << a[i] << " ";
    }
}

/*
OUTPUT


Enter 7 data bits to be transmitted
1 0 0 1 1 0 1

Hamming code : 1 0 0 1 1 1 0 0 1 0 1
Do you want to make any error (Y/N) : Y

Enter the position to make error : 7

Data Received : 1 0 0 1 0 1 0 0 1 0 1
Error detected at position 7
Final Data : 1 0 0 1 1 1 0 0 1 0 1




*/