LeetCode: Integer to Roman

这题因为不知道罗马数是怎么一回事。。就去网上找了答案

 1 class Solution {
 2 public:
 3     string intToRoman(int num) {  
 4       // Start typing your C/C++ solution below  
 5       // DO NOT write int main() function    
 6       char symbol[7] = {'I', 'V', 'X', 'L', 'C', 'D', 'M'};
 7       int scale = 1000;
 8       string ret;
 9       for (int i = 6; i >= 0; i -= 2) {
10           int digit = num / scale;
11           if (digit != 0) {
12               if (digit <= 3) ret = ret + string(digit, symbol[i]);
13               else if (digit == 4) ret = ret + symbol[i] + symbol[i+1];
14               else if (digit == 5) ret = ret + symbol[i+1];
15               else if (digit <= 8) ret = ret + symbol[i+1] + string(digit-5, symbol[i]);
16               else if (digit == 9) ret = ret + symbol[i] + symbol[i+2];
17           }
18           num %= scale;
19           scale /= 10;
20       }
21       return ret;
22     }  
23 };

 1 public class Solution {
 2     public string IntToRoman(int num) {
 3         char[] sym = new char[7]{'I', 'V', 'X', 'L', 'C', 'D', 'M'};
 4         int scale = 1000;
 5         string ans = "";
 6         for (int i = 6; i >= 0; i-=2) {
 7             int digit = num / scale;
 8             if (digit != 0) {
 9                 if (digit <= 3) ans  = ans + new string(sym[i], digit);
10                 else if (digit == 4) ans = ans + sym[i] + sym[i+1];
11                 else if (digit == 5) ans = ans + sym[i+1];
12                 else if (digit <= 8) ans = ans + sym[i+1] + new string(sym[i], digit-5);
13                 else if (digit == 9) ans = ans + sym[i] + sym[i+2];
14             }
15             num %= scale;
16             scale /= 10;
17         }
18         return ans;
19     }
20 }

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