What will be the time complexity for this code?
public int coinChange(int[] coins, int amount){
if(coins == null || coins.length == 0 || amount < 1) return 0;
Deque<Integer> queue = new ArrayDeque<Integer>();
Set<Integer> visited = new HashSet<Integer>();
queue.addFirst(amount);
visited.add(amount);
int level = 0;
while(!queue.isEmpty()){
int size = queue.size();
while(size-- > 0){
int curr = queue.removeLast();
if(curr == 0) return level;
if(curr < 0) continue;
for(int coin : coins){
int next = curr - coin;
if(next >= 0 && !visited.contains(next)){
queue.addFirst(next);
visited.add(next);
}
}
}
level++;
}
return -1;
}
