[leetcode] Add Binary

Add Binary

Total Accepted: 31178 Total
Submissions: 124110My Submissions

Question
Solution

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

a =

"11"

b =

"1"

Return

"100"

.

package com.wyt.leetcodeOJ;

public class AddBinary {

public static void main(String[] args) {
System.out.println(addBinary("100", "110010"));
}

public static String addBinary(String a, String b) {
StringBuffer buffer = new StringBuffer();
if(a.length() < b.length()) {
int k = 0;
for (int i = 0; i < a.length(); i++) {
int tmp = a.charAt(a.length()-1-i) + b.charAt(b.length()-1-i) - 96 + k;
if (tmp >= 2) {
k = tmp/2;
} else {
k = 0;
}
buffer.append(tmp%2);
}

for (int i = 0; i < b.length()-a.length(); i++) {
int tmp = k + b.charAt(b.length()-a.length()-1-i) - 48;
if (tmp >= 2) {
k = tmp/2;
} else {
k = 0;
}
buffer.append(tmp%2);
}
if(k != 0) {
buffer.append(k);
}

return buffer.reverse().toString();
} else {
int k = 0;
for (int i = 0; i < b.length(); i++) {
int tmp = (a.charAt(a.length()-1-i)+b.charAt(b.length()-1-i)-96) + k;
if (tmp >= 2) {
k = tmp/2;
} else {
k = 0;
}
buffer.append(tmp%2);
}

for (int i = 0; i < a.length()-b.length() ; i++) {
int tmp = k + a.charAt(a.length()-b.length()-1-i) - 48;
if(tmp >= 2) {
k = tmp/2;
} else {
k = 0;
}
buffer.append(tmp%2);
}
if(k !=0) {
buffer.append(k);
}
return buffer.reverse().toString();
}
}

}