[Leetcode OJ] Roman to integer

Given a roman numeral, convert it to an integer.

Input is guaranteed to be within the range from 1 to 3999.

 

The following is Baidu's explanation of the number of Rome:

 

My code:

1 class solution {2 public: 3 int romantoint (string s) {4 Map <char, int> conversion; 5 conversion. insert (make_pair ('I', 1); 6 conversion. insert (make_pair ('V', 5); 7 conversion. insert (make_pair ('x', 10); 8 conversion. insert (make_pair ('l', 50); 9 conversion. insert (make_pair ('C', 100); 10 conversion. insert (make_pair ('D', 500); 11 conversion. insert (make_pair ('M', 1000); 12 INT ans = 0; 13 for (unsigned I = 0; I <S. size (); I ++) 14 {15 if (s [I] = 'V' | s [I] = 'l' | s [I] = 'D ') // do not place any of the basic numbers V, L, and D as decimal places on the left of the large number. The subtraction method is used to constitute the number of 16 ans + = Conversion [s [I]; 17 else // any one of the basic numbers I, X, and C can constitute the number itself, or the number can be larger than three on the right of a large number;Only one18 {19 if (I <S. size ()-1 & Conversion [s [I] <conversion [s [I + 1]) 20 {21 ans + = Conversion [s [I + 1]-conversion [s [I]; 22 I ++; 23} 24 else25 ans + = Conversion [s [I]; 26} 27} 28 return ans; 29} 30 };