import java.util.Scanner; // 注意类名必须为 Main, 不要有任何 package xxx 信息 public class Main { public static void main(String[] args) { Scanner in = new Scanner(System.in); int n = in.nextInt(); if(n == 1){ System.out.println(true); return; } int[] a = new int[n]; for(int i = 0; i < n; i++)a[i] = in.nextInt(); in.close(); int cover = 0; boolean flag = false; // 用一个覆盖范围来判断,在覆盖范围内的都是可以跳到的 for(int i = 0; i <= cover; i++){ cover = Math.max(cover, i+a[i]); if(cover >= n-1){ flag = true; break; } } System.out.println(flag); } }