LeetCode-Solutions-in-Cpp17

Solutions to high-frequency interview questions of LeetCode in C++17, taking into account both efficiency and comprehensibility.

---

Project maintained by downdemo Hosted on GitHub Pages — Theme by mattgraham

class Solution {
 public:
  int romanToInt(string s) {
    int res = 0;
    int sz = size(s);
    for (int i = 0; i < sz; ++i) {
      switch (s[i]) {
        case 'I': {
          if (i + 1 < sz && s[i + 1] == 'V') {
            ++i;
            res += 4;
          } else if (i + 1 < sz && s[i + 1] == 'X') {
            ++i;
            res += 9;
          } else {
            res += 1;
          }
          break;
        }
        case 'X': {
          if (i + 1 < sz && s[i + 1] == 'L') {
            ++i;
            res += 40;
          } else if (i + 1 < sz && s[i + 1] == 'C') {
            ++i;
            res += 90;
          } else {
            res += 10;
          }
          break;
        }
        case 'C': {
          if (i + 1 < sz && s[i + 1] == 'D') {
            ++i;
            res += 400;
          } else if (i + 1 < sz && s[i + 1] == 'M') {
            ++i;
            res += 900;
          } else {
            res += 100;
          }
          break;
        }
        case 'V': {
          res += 5;
          break;
        }
        case 'L': {
          res += 50;
          break;
        }
        case 'D': {
          res += 500;
          break;
        }
        case 'M': {
          res += 1000;
          break;
        }
        default: {
          break;
        }
      }
    }
    return res;
  }
};