LeetCode 245. Shortest Word Distance III

I was thinking to use unordered_multimap. However, seems like this STL needs to use expand_range method to extract the low_range and high_range of a target word.

It is overall not convenient to use.  Better to use unordered_map<string, vector<int> > ....

#include <vector>
#include <string>
#include <unordered_map>
#include <iostream>
#include <climits>
using namespace std;

/*
  Given a list of words and two words wor1 and word2, return the shortest distance
  between these two words in the list.
  word1 and word2 may be the same, and they represent two individual words in the list.
  for example:
  Assume that words = ["practise", "makes", "perfect", "coding", "makes"]
  Given word1 = "makes", word2 = "coding", return 1
  Given word1 = "makes", word2 = "makes", return 3.
*/

int shortestWordDistance(vector<string>& words, string word1, string word2) {
  unordered_map<string, vector<int> > hash;
  for(int i = 0; i < words.size(); ++i) {
    hash[words[i]].push_back(i);
  }
  int minDistance = INT_MAX;
  if(word1 == word2) {
    for(int i = 0; i < hash[word1].size(); ++i) {
      minDistance = min(minDistance, abs(hash[word1][i+1] - hash[word1][i]));
    }
  } else {
    for(int i = 0; i < hash[word1].size(); ++i) {
      for(int j = 0; j < hash[word2].size(); ++j) {
        minDistance = min(minDistance, abs(hash[word1][i] - hash[word2][j]));
      }
    }
  }
  return minDistance;
}

int main(void) {
  vector<string> words{"practise", "makes", "perfect", "coding", "makes"};
  cout << shortestWordDistance(words, "makes", "makes") << endl;
  cout << shortestWordDistance(words, "makes", "coding") << endl;
}