JAVA编程的几个简单题目

第一个：
import java.util.Scanner;
import java.util.*;
public class Validate
{
private int n;
/*count_6、count_7、count_8 用来记录收敛那个数字的个数，在这里我记录只要他出现了10次我就认为他收敛与他了
* 还没想到更好的办法，如果不设置这个，就会出现栈溢出，递归不出来了！不过可以看到结果输出结果确实是对的
*/
private int count_6;
private int count_7;
private int count_8;
private Stack stack= new Stack();//栈用来存放素因子
public void scan()
{
Scanner scan = new Scanner(System.in);
try{
n = scan.nextInt();
}catch(NumberFormatException ne){
System.out.println(ne.getMessage());
}
}

public boolean isPrime(int n)
{
if(n>2 && 0 == n%2)//是大于2偶数
{
return false;

}else{

for(int i=3; i{
if(0 == n%i)
return false;
}
return true;
}
}

public void analyze(int n)
{
if(isPrime(n))
{
stack.push(n);
return;
}
if(0 == n%2){
stack.push(2);
n = n/2;
analyze(n);
}else{

for(int i=3; i{
if(isPrime(i)&& 0 == n%i)
{
stack.push(i);
n = n/i;
analyze(n);
}
}

}
}

public void mySort()
{
check(n);
}
public void check(int m)
{
if(isPrime(m)){
m++;
}
else{
analyze(m);
m = 0;
while(!stack.empty())
{
int k = stack.pop().intValue();
m += k;
}
stack.clear();
m++;
}
if(m == 6 || m == 7 || m == 8)
{
if(6 == m)
{
count_6++;
System.out.println("m = " + m);
}else if(7 == m){
count_7++;
System.out.println("m = " + m);
}else if(8 == m){
count_8++;
System.out.println("m = " + m);
}
}
if(count_6 > 10 || count_7 > 10 || count_8 > 10)
{
return;
}
check(m);
}

public static void main(String[] args)
{
Validate v = new Validate();
v.scan();
v.mySort();
}
}

第二个：
import java.util.Scanner;

class MyException extends Exception
{
public MyException(String msg)
{
super(msg);
}
}

public class MyExceptionTest {

public int scan()
{
int a = 0;
Scanner scan = new Scanner(System.in);
try{
a = scan.nextInt();
}catch(NumberFormatException ne){
System.out.println(ne.getMessage());
}
return a;
}

public int cal(int a, int b) throws MyException
{
if(b==0) throw new MyException("自定义异常： 输入的第二个数为0");
else if(a/b<1) throw new MyException("自定义异常： 相除的结果小于1");
else return a/b;

}
public static void main(String[] args) {

MyExceptionTest me = new MyExceptionTest();
System.out.print("请输入第一个数:");
int a = me.scan();
System.out.print("请输入第二个数:");
int b = me.scan();
try{
System.out.println("相除的结果:" + me.cal(a, b));
}catch(MyException e){
System.out.println(e.getMessage());
}
}

}

第三个：
import java.util.*;
import java.util.Map.Entry;

public class CountCharacter {

private static Map map = new LinkedHashMap();

private static final int ONE = 1 ; //没有出现过,则设置其出现一次;

private String content = null;

public void scan()
{
Scanner scan = new Scanner(System.in);
content = scan.nextLine();
}

public void count()
{
String [] text = content.split(" ");
for(int i=0; i{
if (!map.containsKey(text[i])) {
map.put(text[i], ONE);
} else {
int value = map.get(text[i]);
map.put(text[i], value + 1);
}
}
}
public Map sortMap(Map map) {
class MyMap {
private M key;
private N value;
private M getKey() {
return key;
}
private void setKey(M key) {
this.key = key;
}
private N getValue() {
return value;
}
private void setValue(N value) {
this.value = value;
}
}

List> list = new ArrayList>();
for (Iterator i = map.keySet().iterator(); i.hasNext(); ) {
MyMap my = new MyMap();
String key = i.next();
my.setKey(key);
my.setValue(map.get(key));
list.add(my);
}

Collections.sort(list, new Comparator>() {
public int compare(MyMap o1, MyMap o2) {
if(o1.getValue().equals(o2.getValue())) {
return o1.getKey().compareTo(o2.getKey());
}else{
return (int)(o2.getValue().doubleValue() - o1.getValue().doubleValue());
}
}
});

Map sortMap = new LinkedHashMap();
for(int i = 0, k = list.size(); i < k; i++) {
MyMap my = list.get(i);
sortMap.put(my.getKey(), my.getValue());
}
return sortMap;
}

public static void main(String[] args) {
CountCharacter cc = new CountCharacter();
cc.scan();
cc.count();
Map sortMap = cc.sortMap(cc.map);

Iterator> it = sortMap.entrySet().iterator();
Map.Entry entry = null;
int i=0;
while(it.hasNext()&& i<10) {//去前面10个
i++;
entry = (Entry) it.next();
System.out.println(entry.getKey() + " --> " + entry.getValue());
}
}

}

第四个：
import java.util.Scanner;
public class IntegerShape{
public static void main(String[] args){
double a = 0;
int b = 0;
Scanner in = null;
do{
try{
System.out.print("请输入一个的数：");
in=new Scanner(System.in);
a=in.nextFloat();
break;
}catch(Exception ne){
System.out.println("输入数据错误!");
}
}while(true);
do{
try{
System.out.print("请输入显示的行数:");
in=new Scanner(System.in);
b=in.nextInt();
break;
}catch(Exception ne){
System.out.println("输入数据错误!");
}
}while(true);
for(int i=b;i>0;i--)
{
System.out.println(a);
a=a/2;
}
}
}
第五个：
import java.util.Scanner;
import java.util.Vector;

public class MyVector {

private Vector vectorStr = new Vector(); //用来方单词
private Vector vectorInt = new Vector();//用来记录对应下标的单词的个数
private static final int ONE = 1 ; //没有出现过,则设置其出现一次;

private String content = null;

public void scan()
{
Scanner scan = new Scanner(System.in);
content = scan.nextLine();
}

public void countWord()
{
int index = -1;
String [] text = content.split(" ");
for(int i=0; i{
if(vectorStr.contains(text[i])){ //若次单词已经存在与vector中则只要修改对应的个数
index = vectorStr.indexOf(text[i]);
int value = vectorInt.get(index)+1;
vectorInt.setElementAt(value, index);
}
else{//若不存在则添加该单词，同时要初始化对应下标的单词的个数
vectorStr.add(text[i]);
vectorInt.add(ONE);
}
}
System.out.println(vectorStr);
}

public void display()
{
for(int i=0; i{
System.out.println(vectorStr.get(i) + "->" + vectorInt.get(i));
}
}
public static void main(String[] args) {

MyVector mv = new MyVector();
mv.scan();
mv.countWord();
mv.display();
}
}

最后一个了不容易！考虑加点分吧！

import java.util.*;
public class Exp {

private int integer;
private boolean bool = false;
private Stack stack = new Stack();

public void scan()
{
System.out.print("输入一个整数：");
Scanner scan = new Scanner(System.in);
while(true){
try{
integer = scan.nextInt();
break;
}catch(Exception e){
System.out.println("输入错误!");
}
}
}

public void operation()
{

for(int i=1; i {
int sum = 0;
for(int j = i; j<=integer; j++)
{
stack.push(j);
sum += j;
if(sum == integer)
{
int k = 0, n = stack.size();
bool = true;
System.out.print(integer + " = ");
while(!stack.empty())
{
k++;
if(k {
System.out.print(stack.pop().intValue() + " + ");
}
else
{
System.out.print(stack.pop().intValue() + "\n");
}
}
stack.clear();
}else if(sum > integer){
stack.clear();
}
}
}
if(!bool)
System.out.println("该整数没有连续正整数序列！");
}
public static void main(String[] args) {
Exp e = new Exp();
e.scan();
e.operation();
}

}

以上运行过了可以！

（4）测试过
int a=5;
int line=5;
for(int j=1;j{
System.out.println("."+a);
a*=5;
}

本来不想帮你些的，学习靠自己嘛
但是看到上面哪位。。题目要求都没看清楚。哎。
第四题：
import java.util.Scanner;
public class test{
public static void main(String[] args){
Scanner in=new Scanner(System.in);
System.out.print("请输入你想求的整数：");
double a=in.nextInt();
System.out.print("请输入你想得到的行数:");
int b=in.nextInt(); //接受你所需要的行数
for(int i=b;i>0;i--)
{
System.out.println(a);
a=a/2;

}
}
}

3楼说的对
现在就业压力大
还不好好会点东西
以后很麻烦的
这些都是最基础的东西

自己好好写写，不然大四找工作的时候你会后悔的，希望你到时候别记得我这句话。

java全忘了， wubenhua2008答得好啊