Codeforces 376 Div 2

B.java

package codeforces.x376;

import java.util.Scanner;

/**
 * Created by ysharma on 10/16/16.
 */
public class B {

    public static void main(String[] args) {
        new B().doit();
    }

    private void doit(){
        Scanner sc = new Scanner(System.in);

        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; i++){
            a[i] = a[i] % 2; // buy all 2 pizzas

            if(a[i] == 1){
                if(i == N-1){
                    System.out.println("NO");
                    return;
                } else {
                    a[i] = 0;
                    a[i+1] = a[i+1] - 1;
                }
            }
        }

        for(int i : a){
            if(a[i] != 0){ // change this to : if(i != 0){
                System.out.println("NO");
                return;
            }
        }

        System.out.println("YES");

    }
}