Added XOR operation in CRC code.

TODO -> Add encoding function.
NEED TO FIX -> XOR operation only works when the length of data and key
is same.

Codes/CRC.cpp

@@ -0,0 +1,36 @@
+#include <iostream>
+#include <cstring>
+using namespace std;
+
+
+string XOR(string data, string key) {
+    // Dividend is data
+    // Divisor is the primary key, i.e. the key
+    string result = "";
+    int len = data.length();
+
+    // Performing XOR operation
+    for (int i=0; i<len; i++) {
+        if (data[i] == key[i]) {
+            result = result + "0";
+        }
+        else {
+            result = result + "1";
+        }
+    }
+    return result;
+}
+
+int main() {
+	string data, key;
+
+	cout<<endl<<"Enter data:\t";
+	getline(cin, data);
+	cout<<"Enter primary key:\t";
+	getline(cin, key);
+
+	cout<<XOR(data, key);
+
+	return 0;
+
+}