最大数

public String largestNumber(int[] num) {
    ArrayList<String> list = new ArrayList<>();
    for(int i: num){
        list.add(i+"");
    }
    
    Collections.sort(list, new Comparator<String>(){
        public int compare(String left, String right){
            String leftRight = left+right;
            String rightLeft = right+left;
            return leftRight.compareTo(rightLeft);
        }
    });
    
    String result = "";
    for(int i=list.size()-1; i>=0; i--){
        result += list.get(i);
    }
    
    int i=0;
    while(i<result.length() && result.charAt(i)==‘0‘){
        i++;
    }
    if(i==result.length()){
        return "0";
    }
    
    return result.substring(i);
}