Code not getting accepted

#1

//why is the code below not working for Form Biggest //Number question
#include
#include
#include
using namespace std;
bool compare(string a,string b)
{
return a>b;
}
int main()
{
int t;
cin>>t;
while(t–)
{
int n;
cin>>n;
string s[n];
cin.get();
for(int i=0;i<n;i++)
{
cin>>s[i];
}
sort(s,s+n,compare);
for(int i=0;i<n;i++)
{
cout<<s[i];
}
cout<<endl;
}
return 0;
}

#2

please give me 5 min i`ll debug it and get back to u

#3

see since we need to make the biggest number
if we compare a = 909 and b = 9 then comparing a > b would give u true;
this would give a number 9099 since in sorted array 909 comes before 9

so in this case we need the combination 9909 since it is greater than 9099
in the custom comparator
instead of return a > b

check for a+b > b+a
this would check for 9909 & 9099 ( a + b & b+a )
which ever is greater is returned first

so

bool compare(string a,string b)
{
return a+b>b+a;
}
is the correct comparator

#4

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