LeetCode: Add Binary

C++:

 1 class Solution {
 2 public:
 3     string addBinary(string a, string b) {
 4         // Start typing your C/C++ solution below
 5         // DO NOT write int main() function
 6         if (a.size() > b.size()) b = string(a.size()-b.size(), '0') + b;
 7         if (a.size() < b.size()) a = string(b.size()-a.size(), '0') + a;
 8         for (int i = 0; i < a.size(); i++) a[i] += int(b[i]-'0');
 9         int carry = 0;
10         for (int i = a.size()-1; i >= 0; i--) {
11             a[i] += carry;
12             carry = (a[i]-'0') / 2;
13             if (a[i] > '1') a[i] = '0' + (a[i]-'0') % 2;
14         }
15         if (carry) a = '1'+a;
16         return a;
17     }
18 };

java: 填补短string前面零字符串的操作很烦

 1 public class Solution {
 2     public String addBinary(String a, String b) {
 3         int aLen = a.length();
 4         int bLen = b.length();
 5         for (int i = 0; i < Math.abs(aLen - bLen); i++)
 6         {
 7             if (aLen < bLen)
 8             {
 9                 a = "0" + a;
10             }
11             else
12             {
13                 b = "0" + b;
14             }
15         }
16         char[] cs1 = a.toCharArray();
17         char[] cs2 = b.toCharArray();
18         char[] cs3 = new char[a.length()];
19         int c = 0;
20         for (int i = a.length()-1; i >= 0; i--)
21         {
22             int tmp = c + (cs1[i] - '0') + (cs2[i] - '0');
23             c = tmp / 2;
24             cs3[i] = (char)('0' + tmp % 2);
25         }
26         String ans = new String(cs3);
27         if (c > 0)
28         {
29             ans = "1" + ans;
30         }
31         return ans;
32     }
33 }

posted @ 2013-03-15 14:01 ying_vincent 阅读(159) 评论(0) 收藏举报

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