Minimum Distance of Two Words in a Sentence - Amazon Top Interview Questions


Problem Statement :


Given the strings text, word0, and word1, return the smallest distance between any two occurrences of word0 and word1 in text, measured in number of words in between. If either word0 or word1 doesn't appear in text, return -1.

Constraints

word0 and word1 are different.
n ≤ 200,000 where n is the length of text.

Example 1

Input
text = "dog cat hello cat dog dog hello cat world"

word0 = "hello"
word1 = "world"

Output
1

Explanation
There's only one word "cat" in between the hello and world at the end.


Solution :



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                        Solution in C++ :

int solve(string text, string word0, string word1) {
    int i = -1, j = -1, k = 0;
    istringstream ss(text);
    string w;
    int ans = INT_MAX;
    while (ss >> w) {
        ++k;
        if (w == word0) {
            if (j != -1) ans = min(ans, k - j - 1);
            i = k;
        }
        if (w == word1) {
            if (i != -1) ans = min(ans, k - i - 1);
            j = k;
        }
    }
    return ans == INT_MAX ? -1 : ans;
}
                    


                        Solution in Java :

import java.util.*;

class Solution {
    public int solve(String text, String word0, String word1) {
        int w0 = -1;
        int w1 = -1;
        int min = Integer.MAX_VALUE;
        String[] words = text.split(" ");

        for (int i = 0; i < words.length; i++) {
            if (words[i].equals(word0)) {
                w0 = i;
            }

            if (words[i].equals(word1)) {
                w1 = i;
            }

            if (w0 != -1 && w1 != -1) {
                int diff = (int) Math.abs(w0 - w1) - 1;
                min = Math.min(min, diff);
            }
        }
        if (w0 == -1 || w1 == -1) {
            return -1;
        }

        return min;
    }
}
                    


                        Solution in Python : 
                            
int solve(string text, string word0, string word1) {
    int i = -1, j = -1, k = 0;
    istringstream ss(text);
    string w;
    int ans = INT_MAX;
    while (ss >> w) {
        ++k;
        if (w == word0) {
            if (j != -1) ans = min(ans, k - j - 1);
            i = k;
        }
        if (w == word1) {
            if (i != -1) ans = min(ans, k - i - 1);
            j = k;
        }
    }
    return ans == INT_MAX ? -1 : ans;
}


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