PermCheck 100% Solution in Javascript

Question

app.codility.com

My Solution

app.codility.com

function solution(A) {
    
    let count = [];
    
    for (let i = 0; i < A.length; i++) {
        if (A[i] > A.length+1)
            return 0;
        
        if (count[A[i]-1] === undefined)
            count[A[i]-1] = 1;
        else
            return 0;
    }
    
    for (let i = 0; i < count.length; i++) {
        if (count[i] === undefined)
            return 0;
    }
    
    return 1;

}

Note

• Perm starts at 1 and Array Index starts at 0