[Leetcode] Largest Number

#include<bits/stdc++.h>using namespace std;class Solution {public:    string largestNumber(vector<int>& nums) {        vector<string> numStrs;        for(auto it = nums.begin(); it != nums.end(); it++){            /*stringstream ss;            ss << *it;            string ns;            ss >> ns;            numStrs.push_back(ns);*/            ostringstream oss;            oss << *it;            numStrs.push_back(oss.str());        }        /*sort(numStrs.begin(), numStrs.end(),[](const string& a, const string& b){            int len = min(a.length(), b.length());            int i;            for(i = 0; i < len; i++){                if(a[i] == b[i]) continue;                else return a[i] > b[i];            }            if(i == len) return a.length() > b.length();        });*/        sort(numStrs.begin(), numStrs.end(), [](const string& a, const string& b){            string ab(a+b), ba(b+a);            for(int i = 0; i < ab.length(); i++){                if(ab[i] == ba[i]) continue;                return ab[i] > ba[i];            }            return false;  //！！这里必须有返回值，并且不能写true，否则会运行时错误！！！        });        string ret;        if(*numStrs.begin() == "0")  //特判，如果全是0，返回0。否则会得到"00...0"            return "0";        for(auto it = numStrs.begin(); it != numStrs.end(); it++){            ret += *it;        }        return ret;    }    /*string largestNumber2(vector<int>& nums) {        int N = nums.size();        vector<string> numStrs(N);        for(int i = 0; i < N; i++){            stringstream ss;            ss << nums[i];            string ns;            ss >> ns;            numStrs[i] = ns;        }        sort(numStrs.begin(), numStrs.end(), cmp);        string ret = numStrs[0];        if(ret != "0")            for(int i = 1; i < N; i++) ret += numStrs[i];        return ret;    }    */};int main(){    Solution sol;    int arr[5] = {34, 25,10, 17, 19};    cout << sizeof(arr) << endl;    vector<int> var({2,2,2});    cout << sol.largestNumber(var) << endl;}