三道Java算法面试题

下面是某些企业常见的算法面试试题，现总结如下，仅供学员参考与学习。

1.比较两个字符串如果不等返回True？

答案：

Java代码



package com.test.kaoshi;

public class StringDemo {

private static String a = "abc";

private static String b = "abcg";

public static boolean equalString() {

if (a.equals(b)) {

return false;

} else {

return true;

}

}

public static void main(String[] args) {

StringDemo sd = new StringDemo();

System.out.println("主要考察返回Boolean变量和字符串比较使用的方法?+sd.equalString());

}

}

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plaincopy

package com.test.kaoshi;

public class StringDemo {

private static String a = "abc";

private static String b = "abcg";

public static boolean equalString() {

if (a.equals(b)) {

return false;

} else {

return true;

}

}

public static void main(String[] args) {

StringDemo sd = new StringDemo();

System.out.println("主要考察返回Boolean变量和字符串比较使用的方法?+sd.equalString());

}

}

2.随机产生20个字符并且排序？

答案：

Java代码



package com.test.kaoshi;

import java.util.HashSet;

import java.util.Iterator;

import java.util.Random;

import java.util.Set;

import java.util.TreeSet;

public class RadomDemo {

/**

* 随机产生20个字符串并且字符串不能重复 且进行排序

* @param random

* @param len

* @return

*/

public Set getChar(){

Set numberSet01 = new HashSet();

Random rdm = new Random();

char ch;

while(numberSet01.size()<20){

int rdGet = Math.abs(rdm.nextInt())%26+97;//产生97到122的随机数a-z值

ch=(char)rdGet;

numberSet01.add(ch);

//Set中是不能放进重复的值的，当它有20个时，就满足你的条件了

}

return numberSet01;

}

public static void main(String[] args) {

RadomDemo rd = new RadomDemo();

Set numberSet01=rd.getChar();

Set numberSet = new TreeSet();

numberSet.addAll(numberSet01);

for(Iterator it=numberSet01.iterator();it.hasNext();){

System.out.print(it.next());

}

System.out.println();

for(Iterator it=numberSet.iterator();it.hasNext();){

System.out.print(it.next());

}

}

}

[java] view
plaincopy

package com.test.kaoshi;

import java.util.HashSet;

import java.util.Iterator;

import java.util.Random;

import java.util.Set;

import java.util.TreeSet;

public class RadomDemo {

/**

* 随机产生20个字符串并且字符串不能重复 且进行排序

* @param random

* @param len

* @return

*/

public Set getChar(){

Set numberSet01 = new HashSet();

Random rdm = new Random();

char ch;

while(numberSet01.size()<20){

int rdGet = Math.abs(rdm.nextInt())%26+97;//产生97到122的随机数a-z值

ch=(char)rdGet;

numberSet01.add(ch);

//Set中是不能放进重复的值的，当它有20个时，就满足你的条件了

}

return numberSet01;

}

public static void main(String[] args) {

RadomDemo rd = new RadomDemo();

Set numberSet01=rd.getChar();

Set numberSet = new TreeSet();

numberSet.addAll(numberSet01);

for(Iterator it=numberSet01.iterator();it.hasNext();){

System.out.print(it.next());

}

System.out.println();

for(Iterator it=numberSet.iterator();it.hasNext();){

System.out.print(it.next());

}

}

}

3.50个人围成一圈数到三和三的倍数时出圈，问剩下的人是谁？在原来的位置是多少？

答案：

Java代码



package com.test.kaoshi;

import java.util.Iterator;

import java.util.LinkedList;

public class YouXi {

public static int removeNM(int n, int m) {

LinkedList ll = new LinkedList();

for (int i = 0; i < n; i++)

ll.add(new Integer(i + 1));

int removed = -1;

while (ll.size() > 1) {

removed = (removed + m) % ll.size();

ll.remove(removed--);

}

return ((Integer) ll.get(0)).intValue();

}

public static void main(String[] args) {

System.out.println(removeNM(50, 3));

}

}