Shortest Word Distance

Problem

Given an array of strings wordsDict and two different strings that already exist in the array word1 and word2, return the shortest distance between these two words in the list.

Constraints

• 2 <= wordsDict.length <= 3 * 104
• 1 <= wordsDict[i].length <= 10
• wordsDict[i] consists of lowercase English letters.
• word1 and word2 are in wordsDict.
• word1 != word2

Solution

The problem Shortest Word Distance can be solved by recording indexes for appearances of word1 or word2 in wordsDict and finding smallest distance between those indexes.

Implementation

class Solution
{
  public:
    int shortestDistance(vector<string> &wordsDict, string word1, string word2)
    {
        int ret = INT_MAX;
        int idx1 = -1, idx2 = -1;

        for (int i = 0; i < wordsDict.size(); i++)
        {
            if (wordsDict[i] == word1)
                idx1 = i;
            else if (wordsDict[i] == word2)
                idx2 = i;

            if (idx1 != -1 && idx2 != -1)
                ret = min(ret, abs(idx1 - idx2));
        }

        return ret;
    }
};