Leetcode160: Largest Number

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

For example, given

[3, 30, 34, 5, 9]

, the largest formed number is

9534330

.

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

class Solution {
public:
static bool compare(string& s1, string& s2)
{
return (s1+s2)>(s2+s1);
}
string largestNumber(vector<int>& nums) {
vector<string> num(nums.size());
for(int i = 0; i < nums.size(); i++)
{
num[i] = to_string(nums[i]);
}
sort(num.begin(), num.end(), compare);
string res;
bool flag = false;
for(int i = 0; i < num.size(); i++)
{
if(num[i] != "0"){
res += num[i];
flag = true;
}
else if(flag)
{
res += num[i];
}
}
if(!flag) res.push_back('0');
return res;
}
};