10_CommonCharacterCount

int commonCharacterCount(String s1, String s2) {
    int counter = 0 ; 
    int[] u1 = new int[123];    //a-97 z-122
    
    for(int i = 0 ; i < s1.length() ; i++){
        int index = (int)s1.charAt(i);
        u1[index]++;
    }
    
    for(int i = 0 ; i < s2.length() ; i++){
        int index = (int)s2.charAt(i);
        if(u1[index]>=1){
            counter++;
            u1[index]--;
        }
    }
    
    
    return counter; 
}

/**
Given two strings, find the number of common characters between them.

Example

For s1 = "aabcc" and s2 = "adcaa", the output should be
commonCharacterCount(s1, s2) = 3.

Strings have 3 common characters - 2 "a"s and 1 "c".

Input/Output

[execution time limit] 3 seconds (java)

[input] string s1

A string consisting of lowercase latin letters a-z.

Guaranteed constraints:
1 ≤ s1.length ≤ 15.

[input] string s2

A string consisting of lowercase latin letters a-z.

Guaranteed constraints:
1 ≤ s2.length ≤ 15.

[output] integer
**/