Roman to Integer

 1  inline int c2n(char c) {  
 2       switch(c) {  
 3         case ‘I‘: return 1;  
 4         case ‘V‘: return 5;  
 5         case ‘X‘: return 10;  
 6         case ‘L‘: return 50;  
 7         case ‘C‘: return 100;  
 8         case ‘D‘: return 500;  
 9         case ‘M‘: return 1000;  
10         default: return 0;  
11       }  
12     }  
13 class Solution {
14 public:
15     int romanToInt(string s) {
16     
17        
18       // Start typing your C/C++ solution below  
19       // DO NOT write int main() function  
20       int result=0; 
21       int len=s.length();
22       result=c2n(s[0]);
23       for(int i =1; i< len; i++)  
24       {  
25         if(c2n(s[i]) > c2n(s[i-1]))  
26         {  
27           result +=(c2n(s[i]) - 2*c2n(s[i-1]));  
28         }  
29         else  
30         {  
31           result += c2n(s[i]);  
32         }  
33       }  
34       return result;  
35     }  
36 };