2022年最全数据结构与算法面试题附答案解析大汇总

public class Demo13 {
    public static void main(String args[]) {
        int sum, i;
        for (sum = 2; sum <= 100; sum++) {
            for (i = 2; i <= sum / 2; i++) {
                if (sum % i == 0)
                    break;
            }
            if (i > sum / 2)
                System.out.print(sum + " ");
        }
        System.out.println("都是素数");
    }
}

public class Demo131 {
	public static void main(String args[]) {
		int w = 1;
		for (int i = 2; i <= 100; i++) {
			for (int j = 2; j < i; j++) {
				w = i % j;
				if (w == 0)
					break;
			}
			if (w != 0)
				System.out.print(i + " ");
		}
		System.out.println("都是素数");
	}
}

2 3 5 7 11 13 17 19 23 29 31 37 41 43 47 53 59 61 67 71 73 79 83 89 97 都是素数

public class Demo07 {
    static char[] m = { 'a', 'b', 'c' }; 
    static char[] n = { 'x', 'y', 'z' };
    public static void main(String[] args) {
        for (int i = 0; i < m.length; i++) { 
            for (int j = 0; j < n.length; j++) {
                if (m[i] == 'a' && n[j] == 'x') {
                    continue;
                } else if (m[i] == 'a' && n[j] == 'y') {
                    continue;
                } else if ((m[i] == 'c' && n[j] == 'x')
                        || (m[i] == 'c' && n[j] == 'z')) {
                    continue;
                } else if ((m[i] == 'b' && n[j] == 'z')
                        || (m[i] == 'b' && n[j] == 'y')) {
                    continue;
                } else
                    System.out.println(m[i] + " vs " + n[j]);
            }
        }
    }
}

public class Demo071 {
    public String a, b, c;
    public Demo071(String a, String b, String c) {
        this.a = a;
        this.b = b;
        this.c = c;
    }

    public static void main(String[] args) {
    	Demo071 arr_a = new Demo071("a", "b", "c");
        String[] b = { "x", "y", "z" };
        for (int i = 0; i < 3; i++) {
            for (int j = 0; j < 3; j++) {
                for (int k = 0; k < 3; k++) {
                	Demo071 arr_b = new Demo071(b[i], b[j], b[k]);
                    if (!arr_b.a.equals(arr_b.b) & !arr_b.b.equals(arr_b.c)
                            & !arr_b.c.equals(arr_b.a) & !arr_b.a.equals("x")
                            & !arr_b.c.equals("x") & !arr_b.c.equals("z")) {
                        System.out.println(arr_a.a + " vs " + arr_b.a);
                        System.out.println(arr_a.b + " vs " + arr_b.b);
                        System.out.println(arr_a.c + " vs " + arr_b.c);
                    }
                }
            }
        }
    }
}

a vs z
b vs x
c vs y

	*
  ***
 *****
*******
 *****
  ***
   *

public class Demo08 {
    public static void main (String[]args){
        int lay = 7;
        for(int m = 1; m <=(lay+1)/2; m++){
            for(int b = 1; b <=(lay+1)/2-m ; b++)
                System.out.print(" ");
            for(int c = 1; c <= m*2-1; c++)
                System.out.print("*");    
            System.out.println();
        }

        for(int d =(lay+1)/2-1;d >= 1; d --){
            for(int b = 1; b <= (lay+1)/2-d; b++)
                System.out.print(" ");
            for(int c = (lay+1)/2-d; c <=(lay+1)/2-2+d; c ++)
                System.out.print("*");    
            System.out.println();
        }
    }
}

	*
  ***
 *****
*******
 *****
  ***
   *

public class Demo09 {
    public static int getAge(int n) {
        if (n == 1) {
            return 10;
        }
        return 2 + getAge(n - 1);
    }
    public static void main(String[] args) {
        System.out.println("第五个的年龄为" + getAge(5));
    }
}

第五个的年龄为18

package com.jingxuan.system;

public class Sphere {
	public static void main(String[] args) {
		double s = 0;
		double t = 100;
		for (int i = 1; i <= 10; i++) {
			s += t;
			t = t / 2;
		}
		System.out.println("第10次落地时，共经过" +s+ "米");
		System.out.println("第10次反弹" +t+ "米");

	}
}

第10次落地时，共经过199.8046875米
第10次反弹0.09765625米

import java.util.Scanner;
public class Demo03 {
    private static Scanner in;

	public static void fenjie(int n) {
        for (int i = 2; i <= n; i++) {
            if (n % i == 0) {
                System.out.print(i);
                if(n!=i){
                    System.out.print("*");
                }
                fenjie(n/i);
            }
        }
        System.exit(0);
    }

    public static void main(String[] args) {
        in = new Scanner(System.in);
        System.out.println("请输入N的值：");
        int n = in.nextInt();
        System.out.print( "分解质因数：" + n +"=");
        fenjie(n);
    }
}

请输入N的值：
100
分解质因数：100=2*2*5*5

import java.util.Scanner;
public class Demo10 {

    private static Scanner in;

	public static void main(String[] args) {
        System.out.println("请输入数字：");
        in = new Scanner(System.in);
        String str = in.next();
        if (str.matches("\\d+")) {
            System.out.print("输入的是" + str.length() + "位数");
            StringBuffer buf = new StringBuffer(str);
            System.out.println("逆序打印：" + buf.reverse());
        }
    }
}

请输入数字：
871236
输入的是6位数，逆序打印：632178

s=s1+s2+...+sn
t=t1+t2+...+tm
|n-m|<=1

输入: s1 = "aabcc", s2 = "dbbca", s3 = "aadbbcbcac"
输出: true

输入: s1 = "aabcc", s2 = "dbbca", s3 = "aadbbbaccc"
输出: false

class Solution {

	public static void main(String[] args) {
		String s1 = "ab", s2 = "cd", s3 = "acbd";
		System.out.println(isInterleave(s1, s2, s3));
	}

	public static boolean isInterleave(String s1, String s2, String s3) {
		if ((s1.length() + s2.length()) != s3.length())
			return false;

		boolean[][] dp = new boolean[s2.length() + 1][s1.length() + 1];

		dp[0][0] = true;
		for (int i = 1; i <= s1.length(); i++) {
			dp[0][i] = dp[0][i - 1] && s1.charAt(i - 1) == s3.charAt(i - 1) ? true : false;
		}

		for (int i = 1; i <= s2.length(); i++) {
			dp[i][0] = dp[i - 1][0] && s2.charAt(i - 1) == s3.charAt(i - 1) ? true : false;
		}

		for (int i = 1; i < dp.length; i++) {
			for (int j = 1; j < dp[0].length; j++) {
				dp[i][j] = (dp[i][j - 1] && s1.charAt(j - 1) == s3.charAt(i + j - 1))
						|| (dp[i - 1][j] && s2.charAt(i - 1) == s3.charAt(i + j - 1));
			}
		}
		return dp[s2.length()][s1.length()];
	}
}

true

public class Demo02 {
	public static void main(String args[]) {
		for (int i = 100; i <= 999; i++)
			if (shuixianhua(i) == true)
				System.out.println(i + " ");
	}

	public static boolean shuixianhua(int x) {
		int i = 0, j = 0, k = 0;
		i = x / 100;
		j = (x % 100) / 10;
		k = x % 10;
		if (x == i * i * i + j * j * j + k * k * k)
			return true;
		else
			return false;
	}
}

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