Counting Words With a Given Prefix

Leetcode Problem:

• Counting Words With a Given Prefix

Summary

• Find the number of strings in the array that contain a given prefix.

Approach

• The solution uses a simple loop to iterate over each word in the array
• For each word, it checks if the prefix is present by comparing characters one by one
• If the prefix is found, it increments the answer counter.

Complexity

• O(n*m) where n is the number of words and m is the length of the prefix.

Explanation

• The solution works by iterating over each word in the array and comparing it with the prefix
• It uses two nested loops to compare characters one by one
• The outer loop iterates over each word, and the inner loop compares characters up to the length of the prefix
• If the prefix is found, it increments the answer counter.

Solution Code:

class Solution {
public:
    int prefixCount(vector& words, string pref) {
        int ans = 0;
        for(string word : words){
            int i = 0;
            for( ; i < pref.size(); i++){
                if(pref[i] != word[i]){
                    break;
                }
            }
            if(i == pref.size()){
                ans++;
            }
        }
        return ans;
    }
};