From c1d03dc970991f478afb29763ec63e17b6996a9c Mon Sep 17 00:00:00 2001
From: Kshitij <kshitijk@tuta.io>
Date: Thu, 3 Oct 2024 01:11:43 +0530
Subject: [PATCH] Added full working hamming code.

---
 Codes/Code-A4 (Hamming Code).cpp | 103 +++++++++++++++++++++++++++++++
 1 file changed, 103 insertions(+)
 create mode 100644 Codes/Code-A4 (Hamming Code).cpp

diff --git a/Codes/Code-A4 (Hamming Code).cpp b/Codes/Code-A4 (Hamming Code).cpp
new file mode 100644
index 0000000..30ae775
--- /dev/null
+++ b/Codes/Code-A4 (Hamming Code).cpp	
@@ -0,0 +1,103 @@
+#include <iostream>
+#include <cmath>
+#include <vector>
+using namespace std;
+
+// Function to calculate the number of parity bits needed
+int calculateParityBits(int dataBits) {
+    int parityBits = 0;
+    while (pow(2, parityBits) < dataBits + parityBits + 1) {
+        parityBits++;
+    }
+    return parityBits;
+}
+
+// Function to encode the data using Hamming code
+vector<int> encodeData(vector<int> data) {
+    int dataBits = data.size();
+    int parityBits = calculateParityBits(dataBits);
+    vector<int> encoded(dataBits + parityBits, 0);
+
+    // Set the data bits
+    int j = 0;
+    for (int i = 0; i < encoded.size(); i++) {
+        if (i + 1 == pow(2, j)) {
+            j++;
+        } else {
+            encoded[i] = data[i - j];
+        }
+    }
+
+    // Calculate and set the parity bits
+    for (int i = 0; i < parityBits; i++) {
+        int parityBit = pow(2, i);
+        int sum = 0;
+        for (int j = parityBit - 1; j < encoded.size(); j += 2 * parityBit) {
+            for (int k = 0; k < parityBit; k++) {
+                if (j + k < encoded.size()) {
+                    sum += encoded[j + k];
+                }
+            }
+        }
+        encoded[parityBit - 1] = sum % 2;
+    }
+
+    return encoded;
+}
+
+// Function to check for errors in the encoded data
+int checkForErrors(vector<int> encoded) {
+    int parityBits = calculateParityBits(encoded.size() - calculateParityBits(encoded.size()));
+    int errorPosition = 0;
+
+    for (int i = 0; i < parityBits; i++) {
+        int parityBit = pow(2, i);
+        int sum = 0;
+        for (int j = parityBit - 1; j < encoded.size(); j += 2 * parityBit) {
+            for (int k = 0; k < parityBit; k++) {
+                if (j + k < encoded.size()) {
+                    sum += encoded[j + k];
+                }
+            }
+        }
+        errorPosition += (sum % 2) * parityBit;
+    }
+
+    return errorPosition;
+}
+
+int main() {
+    int dataBits;
+    cout<<"Enter the number of data bits:\t";
+    cin >> dataBits;
+
+    vector<int> data(dataBits);
+    cout<<endl<<"NOTE: Make sure the bits are entered in binary format, separated by spaces.\nEg. 1 0 0 1 (for 4 data bits).";
+    cout<<endl<<"Enter the data bits:\t";
+    for (int i = 0; i < dataBits; i++) {
+        cin >> data[i];
+    }
+
+    vector<int> encoded = encodeData(data);
+    cout<<endl<<"--------------------"<<endl;
+    cout<<"Encoded bits are:\t";
+    for (int bit : encoded) {
+        cout << bit << " ";
+    }
+    cout<<endl<<"--------------------"<<endl;
+
+    cout<<endl<<"Enter the encoded bits:\t";
+    vector<int> receivedEncoded(encoded.size());
+    for (int i = 0; i < encoded.size(); i++) {
+        cin >> receivedEncoded[i];
+    }
+
+    int errorPosition = checkForErrors(receivedEncoded);
+    if (errorPosition == 0) {
+        cout<<"No errors detected."<<endl;
+    } else {
+        cout<<"Error detected at position: "<<errorPosition<<endl;
+    }
+
+    return 0;
+}