Input is guaranteed to be within the range from 1 to 3999.
Thoughts
背下来好了...
Code
class Solution {
public int romanToInt(String s) {
int sum = 0;
for (int i = 0; i < s.length(); i++) {
char c = s.charAt(i);
switch(c) {
case 'M':
sum += 1000;
break;
case 'D':
sum += 500;
break;
case 'C':
sum += 100;
break;
case 'L':
sum += 50;
break;
case 'X':
sum += 10;
break;
case 'V':
sum += 5;
break;
default:
sum += 1;
}
}
if(s.indexOf("IV")!=-1){sum-=2;}
if(s.indexOf("IX")!=-1){sum-=2;}
if(s.indexOf("XL")!=-1){sum-=20;}
if(s.indexOf("XC")!=-1){sum-=20;}
if(s.indexOf("CD")!=-1){sum-=200;}
if(s.indexOf("CM")!=-1){sum-=200;}
return sum;
}
}