Codinggame - Puzzles

Intermediaire - Phone numbers - Numéro de téléphone

var N = +readline();
var ROOT = {};  // All tree node with all numbers
var max = 0;    // number of new keys in trees

for (let i = 0, CR; i < N; i++) {
    
    CR = ROOT; // Current sub root elements with fragments of numbers, we always starts
    
    var s = readline().split('');
    for(let j=0, len=s.length; j < len; j++) {
        if (! CR.hasOwnProperty(s[j])) { // if the current branch have not the current number as a key, add it and increment counter
            CR[s[j]] = {};
            ++max;
        }
        CR = CR[s[j]];
    }
}
print(max); // The number of elements (referencing a number) stored in the structure.