# Coding Challenge Day-30: Problem 2: Nearest Greater to right

Hello! So I’m doing a 30 day coding challenge where I solve a few questions every day and thought of posting them here on my blog so that you guys can join the challenge too!

Welcome to Coding challenge Day 30: Problem 2! Be sure to post your answers, queries etc in the comments!

Problem : Nearest Greater to right: Given an array, print the Next Greater Element for every element. The Next greater Element for an element x is the first greater element on the right side of x in array. Elements for which no greater element exist, consider next greater element as -1.

Sample: int array[]={1,3,2,4}
Output: 3 3 4 -1

Sample input: int array[]= {4, 5, 2, 25}
Output: 5 25 25 -1

I referred to this (LINK) for solution and explanation.

Code:

``````package stacks;

import java.util.Collections;
import java.util.Stack;
import java.util.Vector;

public class Nearest_greater_to_right {

public static Vector ngr (int array[], int size){
Vector v= new Vector();
Stack s= new Stack();

for(int i=size-1; i>=0; i--){
if(s.isEmpty()){
}

else if((int)(s.peek())>array[i]){
}

else if((int)(s.peek())<array[i]){
while ((int)(s.peek())<=array[i] && !s.isEmpty()){
s.pop();
}
if(!s.isEmpty()){
} else{
}

}

s.push(array[i]);
}

Collections.reverse(v);

return v;
}

public static void main (String args[]){
int [] array= {4, 5, 2, 25};
Vector v= ngr(array, array.length);

for(Object obj: v){
System.out.print(obj+ " ");
}
}

}
``````

Happy Learning!!

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