자바 기본 프로 그래 밍 문제(API 단계 테스트)(정 답)
19343 단어 답안
import java.util.Scanner;
public class Test1 {
/**
* , , 1. admin, , : admin
* 2. , : , 2 ( 3 )
*/
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
System.out.println(" :");
for (int i = 1; i <= 3; i++) {
String userName = sc.nextLine();
String passWord = sc.nextLine();
if ("admin".equals(userName) && "admin".equals(passWord)) {
// ,
System.out.println(" admin ");
break;
} else {
if (i == 3) {
// ,
System.out.println(" , .");
} else {
System.out.println(" , " + (3 - i) + " ");
}
}
}
}
}
두 번 째 문제(프로 그래 밍 문제:15 점)
import java.util.Scanner;
public class Test2 {
/**
* , , , , 。
:ABCDEabcd123456!@#$%^
:ABCDEabcd123456!@#$%^ :5 , :4 , :6 , :6
*/
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
System.out.println(" :");
// ,
String line = sc.nextLine();
// 4
int big = 0;
int small = 0;
int num = 0;
int other = 0;
// 1.
char[] arr = line.toCharArray();
// 2. ,
for (int i = 0; i < arr.length; i++) {
char c = arr[i];
// 3.
if(c >= 'A' && c <= 'Z'){
big++;
}else if(c >= 'a' && c <= 'z'){
small++;
}else if(c >= '0' && c <= '9'){
num++;
}else {
other++;
}
}
System.out.println(line + " :"+big+" , :"+small+" , :"+num+" , :"+other+" ");
}
}
세 번 째 문제(프로 그래 밍 문제:15 점)
public class Test3 {
/**
* (1) "25 11 -6 20 102 9",
* (2) , "-6 9 11 20 25 102"
*/
public static void main(String[] args) {
String s = "25 11 -6 20 102 9";
// 1.
String[] sArr = s.split(" ");
// 2. ,
int[] arr = new int[sArr.length];
for (int i = 0; i < sArr.length; i++) {
// 3.
arr[i] = Integer.parseInt(sArr[i]);
}
// 4.
for (int i = 0; i < arr.length - 1; i++) {
for (int j = 0; j < arr.length - 1 - i; j++) {
if(arr[j] > arr[j+1]){
int temp = arr[j];
arr[j] = arr[j+1];
arr[j+1] = temp;
}
}
}
// 5. StringBuffer
StringBuffer sb = new StringBuffer();
for (int i = 0; i < arr.length; i++) {
sb.append(arr[i]+ " ");
}
String result = sb.toString();
System.out.println(result);
}
}
네 번 째 문제(프로 그래 밍 문제:25 점)
public class Test4 {
/**
* MyStringUtil , , : (1)public static char[]
* toCharArray(String str) :
* ( jdk String tocharArray ) (2) public
* static String getSingleString(String str) :
* ( ),
*
* (3)public static boolean isBalancedString(String str):
* true, false, :abccba :abcdecba
*/
public static void main(String[] args) {
System.out.println(MyStringUtil.isBalancedString("abcdecba"));
}
}
class MyStringUtil {
/**
* @param str
*
* @return
*/
public static char[] toCharArray(String str) {
// 1. char ,
char[] arr = new char[str.length()];
for (int i = 0; i < str.length(); i++) {
// 2. charAt , .
arr[i] = str.charAt(i);
}
return arr;
}
public static String getSingleString(String str) {
// aaabbbccc // abc
// abc.contains("d");
// 1.
char[] arr = str.toCharArray();
// 2. ,
StringBuffer sb = new StringBuffer();
// 3.
for (int i = 0; i < arr.length; i++) {
char c = arr[i];
// 4. , .
if (!sb.toString().contains(c + "")) {
// 5.
sb.append(c);
}
}
return sb.toString();
}
public static boolean isBalancedString(String str) {
// 1. StringBuffer
StringBuffer sb = new StringBuffer(str);
// 2.
sb.reverse();
// 3. ,
if (str.equals(sb.toString())) {
return true;
} else {
return false;
}
}
}
다섯 번 째 문제(프로 그래 밍 문제:30 점)
import java.util.Random;
public class Test5 {
/**
* String getStr(char[] chs) , : chs 4 , 1 0-9 ( 0 9) 。
main , :
(1) 26, 26 chs
(2) chs getStr(char[] chs) , ,
*/
public static void main(String[] args) {
char[] arr = {'A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z'};
System.out.println(getStr(arr));
}
public static String getStr(char[] chs){
// , Random
Random r = new Random();
// ,
StringBuffer sb = new StringBuffer();
for(int i = 1; i <= 4; i++){
//
int index = r.nextInt(chs.length);
// ,
sb.append(chs[index]);
}
// nextInt 0-9
int num = r.nextInt(10);
//
sb.append(num);
//
return sb.toString();
}
}