Add Binary

描述

Given two binary strings, return their sum (also a binary string).

For example,

  1. a = "11"
  2. b = "1"

Return 100.

分析

无

代码

  1. // Add Binary
  2. // 时间复杂度O(n)，空间复杂度O(1)
  3. class Solution {
  4.     public String addBinary(String a, String b) {
  5.         StringBuilder result = new StringBuilder();
  6.         int i = a.length() - 1;
  7.         int j = b.length() - 1;
  8.         int carry = 0;
  10.         while(i >= 0 || j >= 0 || carry > 0) {
  11.             int valueA = i < 0 ? 0 : a.charAt(i--) - '0';
  12.             int valueB = j < 0 ? 0 : b.charAt(j--) - '0';
  13.             int sum = valueA + valueB + carry;
  14.             result.insert(0, Character.forDigit(sum % 2, 10));
  15.             carry = sum / 2;
  16.         }
  17.         return result.toString();
  18.     }
  19. }

相关题目

原文: https://soulmachine.gitbooks.io/algorithm-essentials/content/java/string/add-binary.html