/**

*Given a roman numeral, convert it to an integer.

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

*/

class Solution {

public:

int romanToInt(string s) {

int result = 0;

int i = 0;

int res[s.size()+1]= {0};

for(;i < s.size(); i++)

{

switch(s[i])

{

case 'I': res[i] = 1;break;

case 'V': res[i] = 5;break;

case 'X': res[i] = 10;break;

case 'L': res[i] = 50;break;

case 'C': res[i] = 100;break;

case 'D': res[i] = 500;break;

case 'M': res[i] = 1000;break;

default: res[i] = 0;break;

}

}

for(int i = 0; i < s.size(); i++)

result += (res[i]>= res[i+1])?res[i]:-res[i];

return result;

}

};