[LeetCode] 67. Add Binary binary sum (Easy) (JAVA)
Topic Address: https://leetcode.com/problems/plus-one/
Subject description:
Given two binary strings, return their sum (also a binary string).
The input strings are both non-empty and contains only characters 1 or 0.
Example 1:
Input: a = "11", b = "1"
Output: "100"
Example 2:
Input: a = "1010", b = "1011"
Output: "10101"
Subject to the effect
Given two binary string, and return to their (expressed in binary).
And a non-empty input string contains only numbers 0 and 1.
Problem-solving approach
Relatively simple, direct traversal, determine the need to carry
class Solution {
public String addBinary(String a, String b) {
StringBuilder res = new StringBuilder();
int carry = 0;
for (int i = 0; i < a.length() || i < b.length(); i++) {
if (i < a.length()) {
carry += a.charAt(a.length() - 1 - i) - '0';
}
if (i < b.length()) {
carry += b.charAt(b.length() - 1 - i) - '0';
}
res.append((carry % 2));
carry /= 2;
}
if (carry > 0) res.append(carry);
return res.reverse().toString();
}
}
When execution: 3 ms, beat the 54.59% of all users to submit in Java
memory consumption: 38.2 MB, beat the 5.16% of all users to submit in Java
