(Java)LeetCode-67. Add Binary

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

For example,
a = "11"
b = "1"
Return "100".

这道题也是木有什么难度，总体来说和上一题很像。

从后向前遍历一遍即可。注意有进位的情况。

public String addBinary(String a, String b) {int lena = a.length();int lenb = b.length();int com = Math.min(lena, lenb);int c = 0;int temp = 0;StringBuilder sb = new StringBuilder();for(int i = 0; i < com; i++){temp = Character.getNumericValue(a.charAt(lena-- -1)) + Character.getNumericValue(b.charAt(lenb-- -1)) + c;sb.insert(0, temp%2);c = temp / 2;}while(lena > 0){temp = Character.getNumericValue(a.charAt(lena-- -1)) + c;sb.insert(0, temp%2);c = temp / 2;}while(lenb > 0){temp = Character.getNumericValue(b.charAt(lenb-- -1)) + c;sb.insert(0, temp%2);c = temp / 2;}if(c == 1)sb.insert(0, 1);        return sb.toString();    }