【LeetCode】LeetCode——第13题：Roman to Integer

13. Roman to Integer

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Total Accepted: 82120  Total Submissions: 209456  Difficulty: Easy

Given a roman numeral, convert it to an integer.

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

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题目的大概意思是：输入一串罗马数字的字符串，输出对应的整数。

这道题难度等级：简单

与第12题的功能相反，思路差不多，整数也在1-3999之间。

为方便处理，我在字符串的最后加上了一个I，这样就不必考虑下标越界的问题了。

代码如下：

class Solution {
public:
    int romanToInt(string s) {
        int table[255];
		table['I'] = 1;		table['V'] = 5;		table['X'] = 10;	table['L'] = 50;
		table['C'] = 100;	table['D'] = 500;	table['M'] = 1000;
		int res = 0;
		s += "I";
		for (int i = 0; i < s.length() - 1; ++i){
            table[s[i]] >= table[s[i + 1]] ? (res += table[s[i]]): (res += table[s[i + 1]] - table[s[i]], ++i);
		}
		return res;
    }
};

也是做了一个表，利用查表法。

提交代码，顺利AC，Runtime: 36 ms。