Careercup - Facebook面试题 - 6139456847347712

2014-05-01 01:50

题目链接

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 }