Careercup - Facebook面试题 - 4892713614835712

2014-05-02 09:54

题目链接

原题：

You have two numbers decomposed in binary representation, write a function that sums them and returns the result. 

Input: 100011, 100100 
Output: 1000111

题目：做二进制加法。

解法：字符串就行了，不需要额外开辟数组。string对象本身就是一个vector，也就是一个数组喽。

代码：

 1 // http://www.careercup.com/question?id=4892713614835712
 2 #include <iostream>
 3 #include <string>
 4 using namespace std;
 5 
 6 string binaryAdd(string &a, string &b)
 7 {
 8     if (a.length() > b.length()) {
 9         return binaryAdd(b, a);
10     }
11     
12     string c;
13     int carry;
14     int na, nb;
15     int bita, bitb;
16     int i;
17 
18     reverse(a.begin(), a.end());
19     reverse(b.begin(), b.end());
20     
21     na = (int)a.length();
22     nb = (int)b.length();
23     carry = 0;
24     for (i = 0; i < nb; ++i) {
25         bita = i < na ? a[i] - '0' : 0;
26         bitb = b[i] - '0';
27         c.push_back((bita ^ bitb ^ carry) + '0');
28         carry = (bita + bitb + carry) > 1;
29     }
30     if (carry) {
31         c.push_back('1');
32     }
33     reverse(c.begin(), c.end());
34 
35     return c;
36 }
37 
38 int main()
39 {
40     string a, b, c;
41     
42     while (cin >> a >> b) {
43         c = binaryAdd(a, b);
44         cout << c << endl;
45     }
46     
47     return 0;
48 }

 

 posted on 2014-05-02 09:59  zhuli19901106  阅读(175)  评论(0)  编辑  收藏  举报