我蒸的服了

#include<bits/stdc++.h>
using namespace std;
struct shu{
	long num;
	int weishu;
	long change;
}a[21];
cmp(shu a,shu b)
{
	return a.change>b.change;
}
int main()
{
	int n,max=-0x3f;
	cin>>n;
	for(int i=1;i<=n;i++)
	{
		cin>>a[i].num;
		int s=a[i].num;	
		a[i].change=a[i].num;
		int k=0;
		while(s)
		{
			k++;
			s/=10;
		}
		if(k>=max)
		max=k;
		a[i].weishu=k;
	}
	for(int i=1;i<=n;i++)
	{
		while(a[i].weishu<max)
		{
			a[i].change*=10;
			a[i].weishu++;
		}
	}
	sort(a+1,a+1+n,cmp);
	for(int i=1;i<=n;i++)
	{
		cout<<a[i].num;
	}
	return 0;
}

有没有大佬看看哪里不对