美团第一题答案，结束之后才调试出来，渣渣import java.util.Arrays;import java.util.Scanner;public class Main {    public static void main(String[] args) {        Scanner sc = new Scanner(System.in);        while(sc.hasNext()){            int n = sc.nextInt();            int[] arr = new int[n];            for(int i=0;i                arr[i]=sc.nextInt();            }            Arrays.sort(arr);            int[] dp = new int[n+1];            dp[0]=1;            dp[1]=1;            for(int i=2;i                while(i                    dp[i] = dp[i-1];                    i++;                }                if(i                    dp[i] = Math.max(dp[i-2]+1,dp[i-1]);                }else{                    dp[i] = Math.max(dp[i-1],dp[i-2])+1;                }            }            System.out.print(dp[n-1]);        }    }}