有n个人正在饭堂排队买海北鸡饭。每份海北鸡饭要25元。奇怪的是，每个人手里只有一张钞票（每张钞票的面值为2550100元），而且饭堂阿姨一开始没有任何零钱。请问饭堂阿姨能否给所有人找零（假设饭堂阿(代

Posted 2020-11-27 是馄饨呀

思路：

一个数组存储n个人的费用，另一个集合来存所要找的零钱，考虑顺序

代码：

import java.util.ArrayList;
import java.util.Scanner;

public class Main{
    public static void main(String[] args) {
        ArrayList<Integer> list = new ArrayList<>();
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int[] arr = new int[n];
        for (int i = 0; i < n; i++) {
            arr[i] = sc.nextInt();
        }
        System.out.println(test(arr, list));
    }

    public static String test(int[] arr, ArrayList<Integer> list) {
        int keyi=0;
        for (int i = 0; i < arr.length; i++) {
            if (arr[i] == 25) {
                list.add(arr[i]);
                keyi++;
            
            } else if (arr[i] == 50) {
                for (int j = 0; j < list.size(); j++) {
                    if (list.get(j) == 25) {
                        list.remove(j);
                        list.add(50);
                        keyi++;
                        break;
                    }

                }
            }
            else if (arr[i] == 100) {
                int twenteFive=0;
                int fifty=0;
                for (int j = 0; j<list.size(); j++) {
                    if(list.get(j)==25) {
                        twenteFive++;
                    }else if(list.get(j)==50) {
                        fifty++;
                    }
                }

                if(twenteFive>=3 || fifty>=1&&twenteFive>=1) {
                    if(fifty>=1&&twenteFive>=1) {
                        for (int j = 0; j < list.size(); j++) {
                            if(list.get(j)==25) {
                                list.remove(j);
                                break;
                            }
                        }
                        
                        for (int j = 0; j <list.size(); j++) {
                            if(list.get(j)==50) {
                                list.remove(j);
                                break;
                            }
                        }
                        keyi++;
                        
                    }
                    else if(twenteFive>=3) {
                    
                        for (int j = 0; j <3; j++) {
                            for (int j2 = 0; j2 < list.size(); j2++) {
                                if(list.get(j2)==25) {
                                    list.remove(j2);
                                    break;
                                }
                            }
                        }
                        keyi++;
                        
                    
                    }
                }
            }
        }


        if (keyi==arr.length){
            return "YES";
        }else {
            return "NO";
        }


    }
}