LeetCode 13. Roman to Integer

Given a roman numeral, convert it to an integer.

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

 

水题一枚，注意搞清楚规则，注意空间分配

class Solution {
public:
    int romanToInt(string s) {
        int length = s.size();
        int p[length + 1] = {0};
        int num = 0;
        for(int i = 0;i < length;i++)
        {
            switch(s[i])
            {
                case 'I':
                    p[i] = 1;
                    break;
                case 'X':
                    p[i] = 10;
                    break;
                case 'C':
                    p[i] = 100;
                    break;
                case 'M':
                    p[i] = 1000;
                    break;
                case 'V':
                    p[i] = 5;
                    break;
                case 'L':
                    p[i] = 50;
                    break;
                case 'D':
                    p[i] = 500;
                    break;
                default:
                    p[i] = 0;
                    break;
            }
        }
        for(int i = 0;i < length;i++)
        {
            if(p[i] >= p[i + 1])
            {
                num = num + p[i];
            }                
            if(p[i] < p[i + 1])
            {
                num = num - p[i];
            }
        }
        return num;
    }
};