Algorithm: Max Counters

Question

I have the following problem:

You are given N counters, initially set to 0, and you have two possible operations on them:

• increase(X) − counter X is increa

Answer 1

A 100/100 solution in php

function solution($N, $A){
    $cond     = $N + 1;
    $cur_max  = 0;
    $last_upd = 0;
    $cnt_arr  = array();
    $cnt      = count($A);
    for($i = 0; $i < $cnt; $i++){
        $cur = $A[$i];
        if($cur == $cond){
            $last_upd = $cur_max;
        }
        else{
            $pos = $cur - 1;
            if(!isset($cnt_arr[$pos])){
                $cnt_arr[$pos] = 0;
            }
            if($cnt_arr[$pos] < $last_upd){
                $cnt_arr[$pos] = $last_upd + 1;
            }
            else{
                $cnt_arr[$pos] ++;
            }
            if($cnt_arr[$pos] > $cur_max){
                $cur_max = $cnt_arr[$pos];
            }
        }
    }
    for($i = 0; $i < $N; $i++){
        if(!isset($cnt_arr[$i])){
            $cnt_arr[$i] = 0;
        }
        if($cnt_arr[$i] < $last_upd){
            $cnt_arr[$i] = $last_upd;
        }
    }
    return $cnt_arr;
}