Get Missing Numbers

getmissing.js

// only support up to the n = 32
// assuming Math.log() is O(1)
function compute(array, max){
    max = max || 32;
    var sum = Math.pow(2,max)-1;
    array.forEach(function(v){
        sum -= Math.pow(2,v-1);
    });

    var result = [];
    
    while (sum > 0) {
        var y = Math.ceil(Math.log(sum+1)/Math.log(2));
        sum = sum - Math.pow(2,y-1);
        result.push(y);
    }
    return result;
}
compute([1,2,4,5,8,9,10],15);