013RomanToInteger.java

class Solution {
    public int romanToInt(String Roman) {
         int nums[]=new int[Roman.length()];
		    for(int i=0;i<Roman.length();i++){
		        switch (Roman.charAt(i)){
		            case 'M':
		                nums[i]=1000;
		                break;
		            case 'D':
		                nums[i]=500;
		                break;
		            case 'C':
		                nums[i]=100;
		                break;
		            case 'L':
		                nums[i]=50;
		                break;
		            case 'X' :
		                nums[i]=10;
		                break;
		            case 'V':
		                nums[i]=5;
		                break;
		            case 'I':
		                nums[i]=1;
		                break;
		        }
		    }
		    int sum=0;
		    for(int i=0;i<nums.length-1;i++){
		        if(nums[i]<nums[i+1])
		            sum-=nums[i];
		        else
		            sum+=nums[i];
		    }
		    return sum+nums[nums.length-1];
    }
}