腾讯9.20笔试题，求第三题解答

看上去都不难，可是就是AC不了，可能自己太暴力了。

100，10，0，60，20

求第三题思路

附我的代码如下：

第一题，企鹅号码

import java.util.Scanner;

public class Main {
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        int t = Integer.parseInt(sc.nextLine());
        for (int i = 0; i < t; i++){
            int x = Integer.parseInt(sc.nextLine());

            String str = sc.nextLine();
            if (isNum(str))
                System.out.println("YES");
            else
                System.out.println("NO");
        }


    }
    private static boolean isNum(String s){
        if (s.length() == 11 && s.charAt(0) == '8')
            return true;
        if (s.length() < 11)
            return false;
        int len = s.length();
        String tmp = s.substring(0, len-10);
        if (tmp.contains("8"))
            return true;
        return false;
    }
}

第二题，最短用时

import java.util.*;

public class Main2 {
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        int n = Integer.parseInt(sc.nextLine());
        List<Integer> list = new ArrayList<>();

        for (int i = 0; i < n; i++){
            String[] s = sc.nextLine().split(" ");
            int x = Integer.parseInt(s[0]);
            int y = Integer.parseInt(s[1]);
            for (int j = 0; j < x; j++){
                list.add(y);
            }
        }
        Collections.sort(list);

        int res = Integer.MIN_VALUE;
        int len = list.size();
        for (int i = 0; i < len/2; i++){
            int sum = list.get(i) + list.get(len-i-1);
            res = Math.max(sum, res);
        }

        System.out.println(res);
    }
}

第三题，战斗力平均

public class Main3 {
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        int t = Integer.parseInt(sc.nextLine());
        for (int i = 0; i < t; i++){
            int n = Integer.parseInt(sc.nextLine());
            String[] s = sc.nextLine().split(" ");
            int[] x = new int[s.length];
            for (int j = 0; j < x.length; j++){
                x[j] = Integer.parseInt(s[j]);
            }
            fun(n, x);

        }

    }
    private static void fun(int n, int[] x){
        Arrays.sort(x);
        int sum1 = 0;
        int sum2 = 0;
        int i = 0;
        int count = 0;
        for (; i+1 < n/2; i = i+2){
            sum1 += x[i] + x[n-i-1];
            sum2 += x[i+1] + x[n-i-2];
            count += 2;
        }
        int num = count * 2;

        if (n - num == 3){
            if (sum1 < sum2){
                sum1 += x[i]+x[i+1];
                sum2 += x[i+2];
            }else {
                sum2 += x[i]+x[i+1];
                sum1 += x[i+2];
            }
        }else if (n - num == 2){
            if (sum1 < sum2){
                sum1 += x[i+1];
                sum2 += x[i];
            }else {
                sum2 += x[i+1];
                sum1 += x[i];
            }
        }else if (n - num == 1) {
            if (sum1 < sum2)
                sum1 += x[i];
            else
                sum2 += x[i];
        }

        if (sum1 < sum2)
            System.out.println(sum1 + " " + sum2);
        else
            System.out.println(sum2 + " " + sum1);
    }
}

第四题，找最小数x，并减x

import java.util.Arrays;
import java.util.Scanner;

public class Main4 {
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        String[] s = sc.nextLine().split(" ");
        int n = Integer.parseInt(s[0]);
        int k = Integer.parseInt(s[1]);
        int[] arr = new int[n];
        String[] str = sc.nextLine().split(" ");
        for (int i = 0; i < str.length; i++){
            arr[i] = Integer.parseInt(str[i]);
        }

        Arrays.sort(arr);
        for (int i = 0; i < k; i++){
            int x = findMin(arr);
            System.out.println(x);
            for (int j = 0; j < arr.length; j++){
                if (arr[j] != 0)
                    arr[j] -= x;
            }
        }
    }
    public static int findMin(int[] arr){
        int min = Integer.MAX_VALUE;
        for (int i = 0; i < arr.length; i++){
            if (arr[i] != 0 && arr[i]<min){
                min = arr[i];
                break;
            }
        }
        if (min != Integer.MAX_VALUE)
            return min;
        else
            return 0;
    }
}

第五题，异或

import java.util.Scanner;

public class Main5 {
    public static void main(String[] args){
//        System.out.println(or(5,11));
        Scanner sc = new Scanner(System.in);
        int n = Integer.parseInt(sc.nextLine());
        String[] sa = sc.nextLine().split(" ");
        int[] a = new int[n];
        for (int i = 0; i < n; i++){
            a[i] = Integer.parseInt(sa[i]);
        }
        String[] sb = sc.nextLine().split(" ");
        int[] b = new int[n];
        for (int i = 0; i < n; i++){
            b[i] = Integer.parseInt(sb[i]);
        }

        int res = 0;
        for (int i = 0; i < n; i++){
            for (int j = 0; j < n; j++){
                res = or(res, a[i]+b[j]);
            }
        }
        System.out.println(res);
    }
    private static int or(int a, int b){
        int res = a^b;
        return res;
    }
}