2022-3-19学习博客

卡片

public class 卡片 {
	public static int[] a=new int[10];//卡片中的数字从0到9
	
	public static boolean del(int n) {
		while(n!=0) {
			a[n%10]--;//卡牌个数减1
			if(a[n%10]<0) {//如果卡牌个数小于0
				return false;
			}
			n/=10;
		}
		return true;
	}
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		for(int i=0;i<10;i++) {
			a[i]=2021;//每个数字对应卡片数量均为2021张
		}
		for(int i=1;i<10000;i++) {
			if(!del(i)) {
				System.out.println(i-1);
				break;
			}
		}

	}
}

时间显示

import java.util.Scanner;

public class 时间显示 {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Scanner scanner=new Scanner(System.in);
		long n=scanner.nextLong();
		n/=1000;
		long s=n%60;
		n/=60;
		long f=n%60;
		n/=60;
		long h=n%24;
		System.out.println(String.format("%02d", h)+":"+String.format("%02d", f)+":"+String.format("%02d", s));

	}

}

货物摆放

import java.util.ArrayList;

public class 货物摆放 {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		long n=2021041820210418l;
		int count=0;
		ArrayList<Long> list=new ArrayList<>();
		for(long i=1;i<=Math.sqrt(n);i++) {
			if(n%i==0) {
				list.add(i);
				if(i!=n/i) {
					list.add(n/i);
				}
			}
			
		}
		for(int i=0;i<list.size();i++) {
			for(int j=0;j<list.size();j++) {
				for(int k=0;k<list.size();k++) {
					if(list.get(i)*list.get(j)*list.get(k)==n) {
						count++;
					}
				}
			}
		}
		System.out.println(count);

	}

}

最少砝码

import java.util.Scanner;

public class 最少砝码 {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Scanner scanner = new Scanner(System.in);
		int N = scanner.nextInt();
		int n = 1, w = 1, count = 1;
		while (n + w < N) {
			n += w;
			w *= 3;
			count++;
		}
		System.out.println(count);
	}

}

Trie字典树

public class Trie {
	int count;//单词数量
	int predix;//以该字符结尾的单词数量
	Trie[] nextNode=new Trie[26];
	
	public Trie() {
		count=0;
		predix=0;
	}
	
	public static void addWord(Trie root,String str) {
		if(root==null||str==null) {
			return;
		}
		char[] chars=str.toCharArray();
		for(int i=0;i<chars.length;i++) {
			if(root.nextNode[chars[i]-'a']==null) {
				root.nextNode[chars[i]-'a']=new Trie();
			}
			root=root.nextNode[chars[i]-'a'];
			root.predix++;
		}
		root.count++;
		System.out.println(str+"单词添加成功");
	}
	
	public static int searchWord(Trie root,String str) {
		if(root==null||str==null) {
			return -1;
		}
		
		char[] chars=str.toCharArray();
		for(int i=0;i<chars.length;i++) {
			if(root.nextNode[chars[i]-'a']==null) {
				System.out.println("该单词未加入字典中");
				return 0;
			}
			root=root.nextNode[chars[i]-'a'];
		}
		System.out.println("单词在词典中出现了"+root.count+"次");
		return 1;
	}
}