Leetcode-Solutions/13-roman-to-integer.cpp at main · aghersidev/Leetcode-Solutions · GitHub

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class Solution {
public:
    int romanToInt(string s) {
        int sum = 0;
        int i = 0;
        for (; i < s.length() - 1; i++) {
            char c = s.at(i);
            char c2 = s.at(i + 1);
            if (c == 'I') {
                if (c2 == 'V') {
                    sum += 4;
                    i++;
                } else if (c2 == 'X') {
                    sum += 9;
                    i++;
                } else
                    sum += 1;
            }
            if (c == 'X') {
                if (c2 == 'L') {
                    sum += 40;
                    i++;
                } else if (c2 == 'C') {
                    sum += 90;
                    i++;
                } else
                    sum += 10;
            }
            if (c == 'C') {
                if (c2 == 'D') {
                    sum += 400;
                    i++;
                } else if (c2 == 'M') {
                    sum += 900;
                    i++;
                } else
                    sum += 100;
            }
            if (c == 'V') sum += 5;
            if (c == 'L') sum += 50;
            if (c == 'D') sum += 500;
            if (c == 'M') sum += 1000;

        }
        if (i != s.length()) {
            if (s.at(i) == 'I') sum += 1;
            if (s.at(i) == 'X') sum += 10;
            if (s.at(i) == 'C') sum += 100;
            if (s.at(i) == 'M') sum += 1000;
            if (s.at(i) == 'V') sum += 5;
            if (s.at(i) == 'L') sum += 50;
            if (s.at(i) == 'D') sum += 500;
            return sum;
        }
        return sum;

        // read 2, if it is dec, put first, forward 1, read 2, if it is inc, put
        // comb, forward 2
    }
};