Today I have done leetcode's September LeetCoding Challenge with cpp.

September LeetCoding Challenge 23

Description

Compare Version Numbers

Given two version strings, version1 and version2, compare them. A version string consists of revisions separated by dots '.'. The value of the revision is its integer conversion ignoring leading zeros.

To compare version strings, compare their revision values in left-to-right order. If one of the version strings has fewer revisions, treat the missing revision values as 0.

Return the following:

• If version1 < version2, return -1.
• If version1 > version2, return 1.
• Otherwise, return 0.

Example 1:

Example 2:

Example 3:

Constraints:

• 1 <= version1.length, version2.length <= 500
• version1 and version2 only contain digits and '.'.
• version1 and version2 are valid version numbers.
• All the given revisions in version1 and version2 can be stored in a 32-bit integer.

Solution

class Solution {
  vector<int> parseVersion(const string &version) {
    vector<int> result;
    int current = 0;
    for(auto c : version) {
      if(isdigit(c)) {
        current *= 10;
        current += c - '0';
      } else {
        result.push_back(current);
        current = 0;
      }
    }
    result.push_back(current);
    return result;
  }
public:
  int compareVersion(string version1, string version2) {
    auto v1 = parseVersion(version1);
    auto v2 = parseVersion(version2);
    while(v1.size() != v2.size()) {
      if(v1.size() < v2.size()) {
        v1.push_back(0);
      } else {
        v2.push_back(0);
      }
    }
    if(v1 < v2) return -1;
    if(v1 == v2) return 0;
    return 1;
  }
};

// Accepted
// 89/89 cases passed (0 ms)
// Your runtime beats 100 % of cpp submissions
// Your memory usage beats 38.53 % of cpp submissions (8.5 MB)