leetcode/src/s0014_longest_common_prefix.cpp

#include "s0014_longest_common_prefix.hpp"

string S0014::longestCommonPrefix(vector<string>& strs) {
  string o{""};
  int size = strs.size();
  int minLen = strs.at(0).length();
  for (int i{0}; i < size; i++) {
    if (strs.at(i).length() < minLen) {
      minLen = strs.at(i).length();
    }
  }
  // string index
  for (int i{0}; i < minLen; i++) {
    string tmp = strs.at(0).substr(i, 1);
    // vector index
    for (int j{0}; j < size; j++) {
      if (strs.at(j).substr(i, 1) == tmp) {
        continue;
      } else {
        return o;
      }
    }
    o.append(tmp);
  }
  return o;
}