Program to add two binary strings
Given two binary strings, return their sum (also a binary string).
Example:
Input: a = "11", b = "1" Output: "100"
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The idea is to start from last characters of two strings and compute digit sum one by one. If sum becomes more than 1, then store carry for next digits.
C++
// C++ program to add two binary strings#include<bits/stdc++.h>using namespace std;// This function adds two binary strings and return// result as a third stringstring addBinary(string a, string b){ string result = ""; // Initialize result int s = 0; // Initialize digit sum // Traverse both strings starting from last // characters int i = a.size() - 1, j = b.size() - 1; while (i >= 0 || j >= 0 || s == 1) { // Comput sum of last digits and carry s += ((i >= 0)? a[i] - '0': 0); s += ((j >= 0)? b[j] - '0': 0); // If current digit sum is 1 or 3, add 1 to result result = char(s % 2 + '0') + result; // Compute carry s /= 2; // Move to next digits i--; j--; } return result;}// Driver programint main(){ string a = "1101", b="100"; cout << addBinary(a, b) << endl; return 0;} |
Java
// java program to add// two binary stringspublic class GFG { // This function adds two // binary strings and return // result as a third string static String addBinary(String a, String b) { // Initialize result String result = ""; // Initialize digit sum int s = 0; // Traverse both strings starting // from last characters int i = a.length() - 1, j = b.length() - 1; while (i >= 0 || j >= 0 || s == 1) { // Comput sum of last // digits and carry s += ((i >= 0)? a.charAt(i) - '0': 0); s += ((j >= 0)? b.charAt(j) - '0': 0); // If current digit sum is // 1 or 3, add 1 to result result = (char)(s % 2 + '0') + result; // Compute carry s /= 2; // Move to next digits i--; j--; } return result; } //Driver code public static void main(String args[]) { String a = "1101", b="100"; System.out.print(addBinary(a, b)); }}// This code is contributed by Sam007. |
Python3
# Python Solution for above problem:# This function adds two binary# strings return the resulting stringdef add_binary_nums(x, y): max_len = max(len(x), len(y)) x = x.zfill(max_len) y = y.zfill(max_len) # initialize the result result = '' # initialize the carry carry = 0 # Traverse the string for i in range(max_len - 1, -1, -1): r = carry r += 1 if x[i] == '1' else 0 r += 1 if y[i] == '1' else 0 result = ('1' if r % 2 == 1 else '0') + result carry = 0 if r < 2 else 1 # Compute the carry. if carry !=0 : result = '1' + result return result.zfill(max_len)# Driver codeprint(add_binary_nums('1101', '100'))# This code is contributed# by Anand Khatri |
C#
// C# program to add// two binary stringsusing System;class GFG { // This function adds two // binary strings and return // result as a third string static string addBinary(string a, string b) { // Initialize result string result = ""; // Initialize digit sum int s = 0; // Traverse both strings starting // from last characters int i = a.Length - 1, j = b.Length - 1; while (i >= 0 || j >= 0 || s == 1) { // Comput sum of last // digits and carry s += ((i >= 0)? a[i] - '0': 0); s += ((j >= 0)? b[j] - '0': 0); // If current digit sum is // 1 or 3, add 1 to result result = (char)(s % 2 + '0') + result; // Compute carry s /= 2; // Move to next digits i--; j--; } return result; } // Driver Code public static void Main(){ string a = "1101", b="100"; Console.Write( addBinary(a, b));}}// This code is contributed by Sam007 |
PHP
<?php// PHP program to add two binary strings// This function adds two binary strings// and return result as a third stringfunction addBinary($a, $b){ $result = ""; // Initialize result $s = 0; // Initialize digit sum // Traverse both strings starting // from last characters $i = strlen($a) - 1; $j = strlen($b) - 1; while ($i >= 0 || $j >= 0 || $s == 1) { // Comput sum of last digits and carry $s += (($i >= 0)? ord($a[$i]) - ord('0'): 0); $s += (($j >= 0)? ord($b[$j]) - ord('0'): 0); // If current digit sum is 1 or 3, // add 1 to result $result = chr($s % 2 + ord('0')) . $result; // Compute carry $s = (int)($s / 2); // Move to next digits $i--; $j--; } return $result;}// Driver Code$a = "1101";$b = "100";echo addBinary($a, $b);// This code is contributed by mits?> |
Javascript
<script>// Javascript program to add// two binary strings// This function adds two// binary strings and return// result as a third stringfunction addBinary(a, b){ // Initialize result var result = ""; // Initialize digit sum var s = 0; // Traverse both strings starting // from last characters var i = a.length - 1, j = b.length - 1; while (i >= 0 || j >= 0 || s == 1) { // Comput sum of last // digits and carry s += ((i >= 0)? a.charAt(i).charCodeAt(0) - '0'.charCodeAt(0): 0); s += ((j >= 0)? b.charAt(j).charCodeAt(0) - '0'.charCodeAt(0): 0); // If current digit sum is // 1 or 3, add 1 to result result = String.fromCharCode(parseInt(s % 2) + '0'.charCodeAt(0)) + result; // Compute carry s = parseInt(s/2); // Move to next digits i--; j--; } return result;}//Driver codevar a = "1101", b="100";document.write(addBinary(a, b));// This code is contributed by Amit Katiyar</script> |
Output:
10001
Thanks to Gaurav Ahirwar for suggesting above solution. Please write comments if you find anything incorrect, or you want to share more information about the topic discussed above
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