package NextGreaterElement;
public class Main {
public static void main(String[] args) {
int[] arr = {2, 1, 3, 8, 6, 7, 5};
Stack<Integer> stack = new Stack<>(); //generic function
for (int i = 0; i < arr.length; i++) {
while (!stack.isEmpty() && arr[i] > stack.peek()) {
int rv = stack.pop();
System.out.println(rv + "->" + arr[i]);
}
stack.push(arr[i]);
}
while (!stack.isEmpty()) {
int rv = stack.pop();
System.out.println(rv + "->" + "-1");
}
}
}