Careercup

2014-05-01 01:50

原题：

Microsoft Excel numbers cells as 1...26 and after that AA, AB.... AAA, AAB...ZZZ and so on. 
Given a number, convert it to that format and vice versa.

题目：微软的Office Excel对于每行每列的命名方式是1, 2, 3, ..., 26, AA, AB, ..., ZZ, AAA, ..., ZZZ。请写个函数完成这种“数字”和自然数的互相转换。

解法：数清楚每个长度“数字”的个数，然后分段转换即可。

代码：

 1 // http://www.careercup.com/question?id=6139456847347712
 2 #include <cstdio>
 3 #include <iostream>
 4 #include <string>
 5 using namespace std;
 6 
 7 string intToString(int n)
 8 {
 9     string s = "";
10     
11     if (n <= 26) {
12         while (n > 0) {
13             s.push_back(n % 10 + '0');
14             n /= 10;
15         }
16         reverse(s.begin(), s.end());
17         return s;
18     }
19 
20     int exp;
21     int len;
22 
23     exp = 26;
24     len = 1;
25     while (n > exp) {
26         n -= exp;
27         ++len;
28         exp *= 26;
29     }
30 
31     --n;
32     for (int i = 0; i < len; ++i) {
33         s.push_back(n % 26 + 'A');
34         n /= 26;
35     }
36     reverse(s.begin(), s.end());
37 
38     return s;
39 }
40 
41 int stringToInt(const string &s)
42 {
43     int n = 0;
44     int len = (int)s.length();
45 
46     if (s[0] >= '0' && s[0] <= '9') {
47         sscanf(s.c_str(), "%d", &n);
48         return n;
49     }
50 
51     int exp = 26;
52 
53     for (int i = 1; i < len; ++i) {
54         n += exp;
55         exp *= 26;
56     }
57     exp = 0;
58     for (int i = 0; i < len; ++i) {
59         exp = exp * 26 + (s[i] - 'A');
60     }
61     n += exp;
62     ++n;
63 
64     return n;
65 }
66 
67 int  main()
68 {
69     int n;
70     string s;
71     
72     while (scanf("%d", &n) == 1 && n > 0) {
73         s = intToString(n);
74         n = stringToInt(s);
75         cout << n << ' ' << s << endl;
76     }
77     
78     return 0;
79 }