class Solution {

    public String largestNumber(int[] nums) {
            Stack<Integer> stack = new Stack<>();
        for(int i = 0; i < nums.length;i++){
            int smallest = i;
            for(int j = i+1; j < nums.length; j++){
                if(compare(nums[j], nums[smallest])){
                    smallest = j;
                }
            }
            int temp = nums[i];
            nums[i] = nums[smallest];
            nums[smallest] = temp;
        }

        List<String> list = new ArrayList<>();
        for(int i = 0; i < nums.length;i++){
            while (nums[i]>=10){
                int temp = 0;
                temp = nums[i] % 10;
                nums[i] = nums[i]/10;
                stack.push(temp);
            }
            stack.push(nums[i]);
            while(!stack.isEmpty()){
                list.add(String.valueOf(stack.pop()));
            }
        }

        StringBuilder sb = new StringBuilder();
		for(String s: list)
	            sb.append(s);

		return sb.toString();

    }

    public boolean compare(int a,int b){
        Stack<Integer> stack1 = new Stack<>();
        Stack<Integer> stack2 = new Stack<>();

        while(a>=10){
            int temp = 0;
            temp = a%10;
            a= a / 10;
            stack1.push(temp);
        }
        while (b>=10){
            int temp = 0;
            temp = b%10;
            b = b/10;
            stack2.push(temp);
        }
        if(a<b) return false;
        else if(a>b) return true;
        else{
            if(!stack1.isEmpty()&&!stack2.isEmpty()){

            return compare(numbuilder(stack1),numbuilder(stack2));}

            if(stack1.isEmpty()&& stack2.isEmpty())return true;
            if(stack1.isEmpty()) return a>stack2.pop();
            else return stack1.pop()>b;}
    }

    public int numbuilder(Stack stack){
        List<Integer> list = new ArrayList<>();
        while(!stack.isEmpty()){
                list.add(stack.pop());
                }
        int result1 = 0;
                for(int i = 0 ; i < list.size();i++){
                    result1+= list.get(i)* Math.pow(10, list.size()-1-i);
                }
        return result1;
    }




}