// 線性搜尋
import java.util.Random;
import java.util.Scanner;
class LinearSearch {
public static void main(String[] args) {
Random rand = new Random();
Scanner stdIn = new Scanner(System.in);
final int n = 12; // 元素數
int[] a = new int[n]; // 宣告陣列
for (int j = 0; j < n; j++)
a[j] = rand.nextInt(10);
System.out.print("陣列a的所有元素的值\n{ ");
for (int j = 0; j < n; j++)
System.out.print(a[j] + " ");
System.out.println(" }");
System.out.print("搜尋的數值：");
int key = stdIn.nextInt();
int i;
for (i = 0; i < n; i++)
if (a[i] == key)
break;
if (i < n) // 搜尋成功
System.out.println("該值存在於a[" + i + "]。");
else // 搜尋失敗
System.out.println("該值不存在。");
}
}
----------------------------------------------------------------------------------
// 線性搜尋
import java.util.Random;
import java.util.Scanner;
class LinearSearch {
public static void main(String[] args) {
Random rand = new Random();
Scanner stdIn = new Scanner(System.in);
final int n = 12; // 元素數
int[] a = new int[n]; // 宣告陣列
for (int j = 0; j < n; j++)
a[j] = rand.nextInt(10);
System.out.print("陣列a的所有元素的值\n{ ");
//for (int j = 0; j < n; j++)
//System.out.print(a[j] + " ");
//System.out.println(" }");
for (int j : a)
System.out.print(j + " ");
System.out.print("搜尋的數值：");
int key = stdIn.nextInt();
int i;
for (i = 0; i < n; i++)
if (a[i] == key)
break;
if (i < n) // 搜尋成功
System.out.println("該值存在於a[" + i + "]。");
else // 搜尋失敗
System.out.println("該值不存在。");
}
}
-------------------------------------------------------------------------------
// 線性搜尋
import java.util.Random;
import java.util.Scanner;
class MyP6_7 {
public static void main(String[] args) {
Random rand = new Random();
Scanner stdIn = new Scanner(System.in);
final int n = 12; // 元素數
int[] a = new int[n]; // 宣告陣列
for (int j = 0; j < n; j++)
a[j] = rand.nextInt(10);
System.out.print("陣列a的所有元素的值\n{ ");
//for (int j = 0; j < n; j++)
//System.out.print(a[j] + " ");
//System.out.println(" }");
for (int j : a)
System.out.print(j + " ");
System.out.print("搜尋的數值：");
int key = stdIn.nextInt();
int i;
for (i = n-1; i >= 0; i--) //倒回來找
if (a[i] == key)
break;
if (i < n) // 搜尋成功
System.out.println("該值存在於a[" + (i+1) + "]。");
else // 搜尋失敗
System.out.println("該值不存在。");
}
}
------------------------------------------------------------------------------------
// 線性搜尋
import java.util.Random;
import java.util.Scanner;
class MyP6_7 {
public static void main(String[] args) {
Random rand = new Random();
Scanner stdIn = new Scanner(System.in);
final int n = 12; // 元素數
int[] a = new int[n]; // 宣告陣列
for (int j = 0; j < n; j++)
a[j] = rand.nextInt(10);
System.out.print("陣列a的所有元素的值\n{ ");
//for (int j = 0; j < n; j++)
//System.out.print(a[j] + " ");
//System.out.println(" }");
for (int j : a)
System.out.print(j + " ");
System.out.print("搜尋的數值：");
int key = stdIn.nextInt();
int i;
for (i = n-1; i >= 0; i--) //倒回來找
if (a[i] == key)
break;
if (i < n && i!=-1) // 搜尋成功
System.out.println("該值存在於a[" + (i+1) + "]。");
else // 搜尋失敗
System.out.println("該值不存在。");
}
}
----------------------------------------------------------------------------------------------
// 將陣列元素的順序逆向重整並顯示
import java.util.Random;
import java.util.Scanner;
class ReverseArray {
public static void main(String[] args) {
Random rand = new Random();
Scanner stdIn = new Scanner(System.in);
System.out.print("元素數：");
int n = stdIn.nextInt(); // 輸入元素數
int[] a = new int[n]; // 宣告陣列
for (int i = 0; i < n; i++) {
a[i] = 10 + rand.nextInt(90);
System.out.println("a[" + i + "] = " + a[i]);
}
for (int i = 0; i < n / 2; i++) {
int t = a[i];
a[i] = a[n - i - 1]; //a[i]與a[n-i-1] swap交換
a[n - i - 1] = t;
}
System.out.println("將元素的排列順序逆轉。");
for (int i = 0; i < n; i++)
System.out.println("a[" + i + "] = " + a[i]);
}
}
-----------------------------------------------------------------------------------
// 線性搜尋
import java.util.Random;
import java.util.Scanner;
class MyP6_12 {
public static void main(String[] args) {
int[] a = {0,1,2,3,4,5,6,7,8,9};
for(int i=0 ; i<10 ; ++i){ //i<10,跑幾次,不一定是10
int r = rand.nextInt(9); //0~8
int t;
t=a[r];
a[r]=a[r+1];
a[r+1]=t;
}
for (int v :a)
System.out.print(v+",");
}
}
----------------------------------------------------------------------------
/**
* 處理檔案及目錄
*
* @author (Shieh-Fu Chen)
* @version (V 1.0 2011/06/27)
*
* 執行結果
* ======================================================================
* CD=D:\bobe\toBalaTech\Develop\Java\java2009\tools\npp587
* D:\\fred.txt
*/
import java.util.Scanner;
import java.io.*;
public class MyFile2 {
public static void main (String args[]) throws IOException {
System.out.println("user.dir = " + System.getProperty("user.dir")); // JVM環境變數;取得 user.dir 環境變數的值
System.setProperty("user.dir", "D:/"); // 改變 user.dir 環境變數的值
// java.io.File 這類別主要是處理檔案及目錄的 PathName, 而不是處理檔案的 I/O (開檔, 讀檔, 存檔),
// 下式只是取得 fred.txt 完整目錄名稱, 並沒有建立新檔
String s = new File("fred.txt").getAbsolutePath(); //File class;檔案不存在一樣成立
System.out.println(s);
if (new File(s).exists()) {
Scanner stdIn = new Scanner(System.in);
System.out.println("進行倒數: ");
int x;
System.out.print("正整數值: ");
x = stdIn.nextInt();
if (x == 0)
System.out.println(new File(s).delete());
}
System.out.println("檔案不存在");
}
}
------------------------------------------------------------------------------
/**
* 建立文字檔, 並寫入字串資料
*
* @author (Sung-Lin Chen)
* @version (V 0.1 2011/04/22)
*/
import java.util.Scanner;
import java.io.*;
class MyWriter1 {
public static void main(String[] argv) throws IOException {
// PrintWriter 沒有提供 Append File 的建構子
PrintWriter pWriter = new PrintWriter("d:\\MyWriter1.txt"); //PrintWriter產生一檔案,如有`存在檔案則將內容清空
Scanner stdIn = new Scanner(System.in);
System.out.print("ID：");
String s = stdIn.nextLine(); //nextLine輸入字串,空白亦可
System.out.print("Score：");
int a = stdIn.nextInt();
// 寫入檔案
pWriter.print(s+",");
pWriter.print(a);
// 關閉檔案
pWriter.close();
}
}
-------------------------------------------------------------------------------
/**
* 將輸入成績, 附加在檔案後面
*
* @author (Sung-Lin Chen)
* @version (V 0.1 2011/04/22)
*
*/
import java.util.Scanner;
import java.io.*;
class MyWriter2 {
public static void main(String[] argv) throws IOException{
// FileWriter 有提供 Append File 的建構子, 但是寫入的方法 (write()) 只提供字元及字串資料型態
FileWriter fWriter = new FileWriter("d:\\MyWriter2.txt", true); //FileWriter-->true資料附加
Scanner stdIn = new Scanner(System.in);
System.out.print("Name：");
String n = stdIn.nextLine();
System.out.print("Address：");
String a = stdIn.nextLine();
fWriter.write(n+","); // write() 無法寫入 double 資料
fWriter.write(a);
fWriter.write("\n"); // 在 記事本 中, 並沒有換行, 應如何解決 ?在檔案是以ASC碼的10,13 (微軟),其它OS為10
fWriter.close();
}
}
----------------------------------------------------------------------------------------------
/**
* 輸入五位同學, 國英數三科成績,存入文字檔
*
* @author (Sung-Lin Chen)
* @version (V 0.1 2011/04/22)
*
*/
import java.util.Scanner;
import java.io.*;
class MyWriter3 {
public static void main(String[] argv) throws IOException {
// FileWriter 有提供 Append File 的建構子
FileWriter fWriter = new FileWriter("d:\\MyWriter3.txt", true);
// PrintWriter 有提供好用的寫入方法 print()
PrintWriter pWriter = new PrintWriter(fWriter);
Scanner stdIn = new Scanner(System.in);
System.out.print("學號：");
String n = stdIn.nextLine();
System.out.print("國文：");
int c = stdIn.nextInt();
System.out.print("英文：");
int e = stdIn.nextInt();
System.out.print("數學：");
int m = stdIn.nextInt();
pWriter.print(n+","); // 寫入字串
pWriter.print(c+","); // 寫入整數
pWriter.print(e+","); // 寫入整數
pWriter.print(m); // 寫入整數
// 根據不同作業系統, 寫入正確的換行碼
pWriter.print(System.getProperty("line.separator")); //取得JVM環境變數
pWriter.close();
}
}
-----------------------------------------------------------------------------------------------------------
/**
* 讀出文字檔內容
*
* @author (Sung-Lin Chen)
* @version (V 0.1 2011/04/22)
*/
import java.io.*;
public class MyReader1 {
public static void main(String[] args) throws IOException {
FileReader fileReader = new FileReader("d:\\MyWriter2.txt"); //FileReader讀入檔案;如檔案不存在, 則無法RUN;
BufferedReader bReader = new BufferedReader(fileReader); //緩衝;提供很好用的METHOD readLine()
String s;
while((s = bReader.readLine()) != null ) {
System.out.println(s);
}
bReader.close();
}
}
----------------------------------------------------------------------------------------------------
import java.util.Scanner;
import java.io.*;
class MyReaderWriter {
public static void main(String[] args)throws IOException{
FileWriter fWriter = new FileWriter("d:\\out.txt", false);
FileReader fileReader = new FileReader("d:\\MyWriter2.txt");
BufferedReader bReader = new BufferedReader(fileReader);
String s;
while((s = bReader.readLine()) != null ) {
for (int i=0; i < s.length() ; i++) {
char c = s.charAt(i);
fWriter.write(c==',' ? '$' : c);
/* /* if ( c == ',' )
System.out.print('$');
else
System.out.print(c); */
}
fWriter.write(System.getProperty("line.separator"));
}
fileReader.close();
fWriter.close();
}
}
-------------------------------------------------------------------
/**
* 讀出文字檔內容, 並解析單行文字
*
* @author (Shieh-Fu Chen)
* @version (V 0.1 2011/07/04)
*
*/
import java.io.*;
public class dafumenu {
public static void main(String[] args) throws IOException{
FileReader fileReader = new FileReader("d:\\dafumenu.txt");
BufferedReader bReader = new BufferedReader(fileReader);
String s;
while((s = bReader.readLine()) != null ) {
if (s.equals("[system]"))
System.out.println("system");
else if (s.equals("[account]"))
System.out.println("account");
else if (s.equals("[student]"))
System.out.println("student");
else
System.out.println();
}
fileReader.close();
}
//fileReader.close();
}
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