问题描述
给定两个二进制字符串，要求求出它们的和。题目链接：**点我**
样例输入输出
输入：a = “11”, b = “1”
输出：”100”
输入：a = “1010”, b = “1011”
输出：”10101”
问题解法
此题类似大数相加，直接模拟加法求解过程即可。代码如下：
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| class Solution
{
public String addBinary(String a, String b)
{
StringBuilder sb = new StringBuilder();
int i = a.length() - 1;
int j = b.length() - 1;
int carry = 0;
while (i >= 0 && j >= 0)
{
int first = a.charAt(i) - '0';
int second = b.charAt(j) - '0';
int num = (carry + first + second) % 2;
carry = (carry + first + second) / 2;
sb.append(num);
i--;
j--;
}
while (i >= 0)
{
int temp = a.charAt(i) - '0';
int num = (carry + temp) % 2;
carry = (carry + temp) / 2;
sb.append(num);
i--;
}
while (j >= 0)
{
int temp = b.charAt(j) - '0';
int num = (carry + temp) % 2;
carry = (carry + temp) / 2;
sb.append(num);
j--;
}
if (carry > 0)
{
sb.append(carry);
}
return sb.reverse().toString();
}
}
|