java笔试-科大讯飞2021秋招java笔试

大家都说题简单，可能公司在刷kpi,或者全员面试…

1.求矩阵两个数乘积的最大值

要求：两个数不在同行同列
裂开…4个for循环，看大家好像都是这样a的

import java.util.Scanner;

/**
 * @author liu
 * @Description
 */
public class Main1 {
    public static void main(String[] args) {
        Scanner ss = new Scanner(System.in);
        int n = ss.nextInt();
        int m = ss.nextInt();

        int[][] a = new int[n][m];

        for(int i = 0;i<n;i++){
            for(int j = 0;j<m;j++){
                a[i][j] = ss.nextInt();
            }
        }
        
        int max = -1;
        for(int i = 0;i<n;i++){
            for(int j = 0;j<m;j++){

                //求局部最大值
                int temp = -1;
                for(int x = 0;x<n;x++){
                    for(int y = 0;y<m;y++){
                        if(x!=i&&y!=j){
                            temp = Math.max(temp , a[x][y]);
                        }
                    }
                }

                max = Math.max(max,a[i][j] * temp);
            }
        }
        System.out.print(max);

    }
}

2.数组排序

就简单的数组排序

/**
 * @author liu
 * @Description
 */
public class Main2 {
    public static void main(String[] args) {
        Scanner ss = new Scanner(System.in);
        int n = ss.nextInt();

        int[] a = new int[n];
        for(int i = 0;i<n;i++){
                a[i] = ss.nextInt();
        }

        Arrays.sort(a);
        for (int num: a){
            System.out.print(num + " ");
        }
    }
}

3.二进制数中1的个数

求二进制数中1的个数

/**
 * @author liu
 * @Description
 */
public class Main3 {
    public static void main(String[] args) {

        Scanner ss = new Scanner(System.in);
        int n = ss.nextInt();


        int count = 0;
        while (n!=0){
            if(n%2!=0){
                count++;
            }
            n = n/2;
        }
        System.out.println(count);
    }
}

4.字符串向前移动n位

一直是80%，好像说是还要考虑字符串里面有空格的情况…
看到大佬们的代码好像是移动n要对字符串长度m取模,我是当n>m时，输出原字符串

public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        String m = scanner.nextLine();
        int n = scanner.nextInt();
        n = n % m.length();
        System.out.println(m.substring(n,m.length()) + m.substring(0,n));
    }

/**
 * @author liu
 * @Description
 */
public class Main4 {
    public static void main(String[] args) {
        Scanner ss1 = new Scanner(System.in);

        String str = ss1.nextLine();
        long n = ss1.nextLong();
        if(str.length() == 0) return;
        if((int)n >= str.length()){
            System.out.print(str);
            return;
        }

        for(int i = (int)n;i<str.length();i++){
            System.out.print(str.charAt((int)i));
        }
        for(int i = 0;i<n;i++){
            System.out.print(str.charAt((int)i));
        }

//        String newStr = str + str + "";
//        char[] s = newStr.toCharArray();
//        for (int i = (int)n;i<str.length()+(int)n;i++){
//            System.out.print(s[i]);
//        }


//        char[] s = str.toCharArray();
//        char[] b = new char[(int)n];
//        char[] c = new char[(int)n];
//
//        for(int i = 0;i<(int)n;i++){
//            b[i] = s[i];
//        }
//        for(int i = (int)n;i<s.length;i++){
//            c[i-(int)n] = s[i];
//        }
//
//        str = String.valueOf(c) + String.valueOf(b) + "";
//        System.out.print(str);

    }
}