string_halves.cpp

/*
You are given a string s of even length. Split this string into two halves of equal lengths, and let a be the first half and b be the second half.

Two strings are alike if they have the same number of vowels ('a', 'e', 'i', 'o', 'u', 'A', 'E', 'I', 'O', 'U'). Notice that s contains uppercase and lowercase letters.

Return true if a and b are alike. Otherwise, return false.

 

Example 1:

Input: s = "book"
Output: true
Explanation: a = "bo" and b = "ok". a has 1 vowel and b has 1 vowel. Therefore, they are alike.
Example 2:

Input: s = "textbook"
Output: false
Explanation: a = "text" and b = "book". a has 1 vowel whereas b has 2. Therefore, they are not alike.
Notice that the vowel o is counted twice.
 

Constraints:

2 <= s.length <= 1000
s.length is even.
s consists of uppercase and lowercase letters.
*/

#include<bits/stdc++.h>
class Solution {
public:
    bool halvesAreAlike(string s) {
        set<char> X {'a', 'e', 'i', 'o', 'u', 'A', 'E', 'I', 'O', 'U'};
        int half = s.size() / 2;
        int c = 0, d = 0;
        for(int i = 0; i < half; i++){
            if(X.find(s[i]) != X.end())
                c++;
        }
        for(int i = half; i < s.size(); i++){
            if(X.find(s[i]) != X.end()){
                d++;
            }
        }
        return c == d;
    }
};