题目描述

贪心

import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        //贪心思路：集合思想，相邻两个匹配还是不匹配，发现匹配比不匹配可以出现最优解，四种情况：11、00、1?、0?、?1、?0
        String n = scanner.nextLine();
        char []a = n.toCharArray();
        int res = 0;
        for (int i = 0; i+1 < n.length(); i++) {
           if(a[i]==a[i+1]||a[i]=='?'||a[i+1]=='?'){
               res++;
               i++;
           }
        }


        System.out.println(res);

        scanner.close();
    }
}