LeetCode: 179. Largest Number

题目描述

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

Example 1:

Input: [10,2]
Output: "210"

Example 2:

Input: [3,30,34,5,9]
Output: "9534330"

Note: The result may be very large, so you need to return a string instead of an integer.

解题思路

根据两个相邻的数组成的数的大小，将所有的数字排序。

AC 代码

class Solution {
    static bool cmp(string lhv, string rhv)
    {
       return (lhv+rhv) > (rhv+lhv); 
    }
public:
    string largestNumber(vector<int>& nums) {
        vector<string> numStrs;
        for(size_t i = 0; i < nums.size(); ++i)
        {
            numStrs.push_back(to_string(nums[i]));
        }

        sort(numStrs.begin(), numStrs.end(), cmp);

        string ans;
        for(string str : numStrs)
        {
            ans += str;
        }
        if(!ans.empty() && ans[0] == '0') ans = "0";

        return ans;
    }
};