蓝桥杯（3.21 刷真题）

P8682 [蓝桥杯 2019 省 B] 等差数列

import java.util.Arrays;
import java.util.Scanner;
public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int[] res = new int[n+1];
		for(int i=1;i<=n;i++)
			res[i] = sc.nextInt();
		Arrays.sort(res);//升序排序
		int d = Integer.MAX_VALUE;
		for(int i=2;i<=n;i++) {
			d = Math.min(d,res[i] - res[i-1]);
		}//找到间距的最小值
		int t = res[1];//从第一项开始求和
		int w = 1;//算上第一项
		for(;t<res[n];) {
			t+=d;
			w++;
		}
		System.out.println(w);//项数
	}
}

P8615 [蓝桥杯 2014 国 C] 拼接平方数

import java.util.Scanner;

public class Main {
	public static boolean check1(String s) {
		int t = Integer.valueOf(s);
		int st = (int)Math.sqrt(t);
		
		return st*st == t;
	}
	public static boolean check2(String s) {
		for(int i=1;i<s.length();i++) {
			String s1 = s.substring(0,i);
			String s2 = s.substring(i);
			if(s1.equals("0")||s1.equals("00")||s1.equals("000")||s1.equals("0000")||s1.equals("00000")||s1.equals("000000")) {
				return false;
			}
			if(s2.equals("0")||s2.equals("00")||s2.equals("000")||s2.equals("0000")||s2.equals("00000")||s2.equals("000000")) {
				return false;
			}
			if(check1(s1)&&check1(s2))
				return true;
		}
		return false;
	}
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int l = sc.nextInt();
		int r = sc.nextInt();
		for(int i=l;i<=r;i++) {
			String s = i+"";
			if(check1(s)&&check2(s)) {
				System.out.println(i);
			}
		}
	}
}

import java.util.Scanner;

public class Main {
	public static boolean check1(String s) {
		int t = Integer.valueOf(s);
		if(t == 0)
			return false;
		int st = (int)Math.sqrt(t);
		return st*st == t;
	}
	public static boolean check2(String s) {
		for(int i=1;i<s.length();i++) {
			String s1 = s.substring(0,i);
			String s2 = s.substring(i);
			if(check1(s1)&&check1(s2))
				return true;
		}
		return false;
	}
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int l = sc.nextInt();
		int r = sc.nextInt();
		for(int i=l;i<=r;i++) {
			String s = i+"";
			if(check1(s)&&check2(s)) {
				System.out.println(i);
			}
		}
	}
}