Find longest occurrence of same number in array

Question

Using JavaScript, I\'m trying to find a way to find the longest occurrence of the same number (in this case, 1) in an array.

For instance, here\'s a sample array:

Answer 1

You can use fewer iterations by looking ahead at all matches from a given index, and jumping ahead to the next non-matching item's index.

You can also quit when there are less items left than the maximum you have found.

function maxRepeats(arr){
    var L= arr.length, i= 0, 
    max= 1, count= 0;
    while(L-i > max){
        while(arr[i+count]=== arr[i])++count;
        if(count > max) max= count;
        i+= count;
        count= 0;
    }
    return max;
}
var A= [2, 5, 3, 1, 1, 1, 3, 7, 9, 6, 4, 1, 
1, 1, 1, 1, 4, 7, 2, 3, 1, 1, 4, 3];

maxRepeats(A); returns 5

Finding multiple items that repeat the max number of times is not so easy, since you have to find the max number before you can list them. If you really only need the max number, ignore this:

function mostRepeats(arr, maximum){
    var i= 0, max= maximum || 1, 
    L= arr.length-max, 
    count= 0, index= [];
    while(i max) max= count;
        i+= count;
        count= 0;
    }
    if(max===1) return 'No repeats';
    return maximum? max+' repeats of: '+index.join(', '): mostRepeats(arr, max);
}

var A= [2, 5, 3, 1, 1, 1, 3, 7, 9, 6, 4, 1, 1, 1, 
1, 1, 4, 7, 2, 3, 3, 3, 3, 3, 1, 1, 4, 3];

mostRepeats(A);returns:

5 repeats of: 1 starting at #11, 3 starting at #19