CCF认证201803-1 跳一跳

import java.util.Scanner;
public class Jump {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int totalScore = 0;
        int preScore = 0;
        while(sc.hasNextInt()){
            int flag = sc.nextInt();
            int score = 0;
            if(flag == 0){
                break;
            }else if(flag == 1){
                //跳上方块没有跳到中心，总分+1
                score +=1;
                preScore = 1;
                totalScore += score;
            }else if(flag == 2){
                //跳上方块并且跳到中心，上次分数+2+总分
                if(preScore == 1){
                    score = 2;
                }else{
                    score = preScore + 2;
                }
                preScore = score;
                totalScore += score;
            }
        }
        System.out.println(totalScore);
    }
}