// Construction of Z array keeping the first element equal to length of string
function zArrayHelper(s) {
    s = s.toLowerCase();
    let Z = [s.length];
    let n = s.length;
    let [L, R] = [0, 0];
    let k;
    for (let i = 1; i < n; i++) {
        if (i > R) {
            [L, R] = [i, i];
            while (R < n && s[R - L] == s[R]) {
                R++;
            }
            Z[i] = R - L;
            R--;
        }
        else {
            k = i - L;
            if (Z[k] < R + 1 - i) {
                Z[i] = Z[k];
            }
            else {
                L = i;
                while (R < n && s[R - L] == s[R]) {
                    R++;
                }
                Z[i] = R - L;
                R--;
            }
        }
    }
    return Z;
}

// Returns the sum of length of all the matching longest common prefix
function stringSimilarity(s) {
    // Write your code here
    return zArrayHelper(s).reduce((sum, length) => sum + length, 0);
}