【第十四届蓝桥杯三月真题刷题训练——第 20 天（3.23）& 纸张尺寸 & 最大数字 & 全排列的价值 & 修路】

本文链接：https://blog.youkuaiyun.com/m0_52201500/article/details/129738689

第一题：纸张尺寸

import java.io.*;

public class Main {



    static  BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    static PrintWriter out = new PrintWriter(new OutputStreamWriter(System.out));

    public static void main(String[] args) throws IOException {
        String s = br.readLine();
        int n = Integer.parseInt(String.valueOf(s.charAt(1)));
        int p1 = 1189, p2 = 841;

        for(int i = 0; i < n; i++){
            int tmp = p1 / 2;
            p1 = p2;
            p2 = tmp;
        }

        out.println(p1);
        out.println(p2);


        out.flush();
    }

}

第二题：最大数字

import java.util.Scanner;

public class Main {
    static String str;
    static int a, b, len;
    static long res;
    
    
    static void dfs(int pos, long v) {
        if(pos == len) {
            res = Math.max(res, v);
            return;
        }
        int c = str.charAt(pos) - '0';
        int t = Math.min(a, 9-c);
        a -= t;
        dfs(pos+1, v*10+c+t);
        a += t;
        if(b > c) {
            b -= c+1;
            dfs(pos+1, v*10+9);
            b += c+1;
        }
    }
    
    public static void main(String[] args) throws Exception {
        Scanner s = new Scanner(System.in);
        str = s.next();
        a = s.nextInt();
        b = s.nextInt();
        len = str.length();
        dfs(0, 0);
        System.out.println(res);
    }
}