p67

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LeetCode p67 Add Binary 题解

1.题目：

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

For example,
a = “11”
b = “1”
Return “100”.

题意：

模拟二进制加法，输出二进制和。

2.解题思路:

见代码

3.代码

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public class Solution {
    public String addBinary(String a, String b) {
        int al = a.length() - 1;
		int bl = b.length() - 1;
		int c = 0;
		StringBuilder stringBuilder = new StringBuilder();
		while (al >= 0 || bl >= 0) {
			int sum = 0;
			if (al >= 0)
				sum += a.charAt(al--) - '0';
			if (bl >= 0)
				sum += b.charAt(bl--) - '0';
			sum += c;
			stringBuilder.append(sum % 2);
			c = sum / 2;
		}
		if (c == 1) stringBuilder.append(c);
		return stringBuilder.reverse().toString();// 反转

    }
}

4.一些总结：