Immediate Smaller Element(GeeksForGeeks)
//Java code for immediate smaller problem on geeksforgeeks(School problem-array Section).
import java.util.*;
import java.lang.*;
import java.io.*;
class GFG
{
public static void main (String[] args)
{
Scanner sc=new Scanner(System.in);
int t=sc.nextInt();
while(t-->0)
{
int n=sc.nextInt();
int a[]=new int[n];
for(int i=0;i<n;i++)
{
a[i]=sc.nextInt();
}
for(int i=0;i<n-1;i++)
{
if(a[i+1]<a[i])
System.out.print(a[i+1]+" ");
else
System.out.print(-1+" ");
}
System.out.print(-1);
System.out.println();
}
}
}