2185. Counting Words With a Given Prefix

[Problem]

Array String String Matching

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Intuition

• Brute Force works because constraints are small.

Constraints
1 <= words.length <= 100
1 <= words[i].length, pref.length <= 100

Approach

• For each word in words check if it has pref as prefix prefix.

Complexity Analysis

• Time Complexity: O(n)
  • n: size of words array.
• Space Complexity: O(1)
  • No extra space used.

Code

class Solution {
    public int prefixCount(String[] words, String pref) {
        int cnt = 0;
        for(String str : words){
            // `str` contains `pref` as prefix 
            if(str.startsWith(pref)){
                cnt += 1; // increment cnt
            }
        }
        return cnt;
    }
}