LeetCode题解 -- 排序(179)

Largest Number

Given a list of non negative integers, arrange them such that they form the largest number.

时间复杂度:O(n^2)
空间复杂度:O(n)

public String largestNumber(int[] nums) {
        int length = nums.length;
        if(length == 0)
            return "";
        if(length == 1)
            return String.valueOf(nums[0]);
        List<Integer> sortedList = new ArrayList<>();
        for(int num : nums)
            sortedList.add(num);

        StringBuffer sBuffer = new StringBuffer();

        Collections.sort(sortedList, new Comparator<Integer>() {
            @Override
            public int compare(Integer o1, Integer o2) {
                String s1 = String.valueOf(o1);
                String s2 = String.valueOf(o2);
                int len1 = s1.length();
                int len2 = s2.length();
                int i = 0;
                StringBuffer sb1 = new StringBuffer(s1);
                StringBuffer sb2 = new StringBuffer(s2);
                sb1.append(s2);
                sb2.append(s1);

                while(i < len1 + len2){
                    if(sb1.charAt(i) > sb2.charAt(i)){
                        return -1;
                    }else if(sb1.charAt(i) < sb2.charAt(i)){
                        return 1;
                    }else{
                        i++;
                    }
                }
                return 1;
            }
        });

        if(sortedList.get(0) == 0){
            return "0";
        }
        for(int num : sortedList){
            sBuffer.append(num);
        }
        System.out.println(sortedList);

        return sBuffer.toString();
    }