输入一个字符串，求出该字符串包含的字符集合，按照字母输入的顺序输出。
数据范围：输入的字符串长度满足 
，且只包含大小写字母，区分大小写。
本题有多组输入
[编程题]字符集合
哈希标记
import java.util.Scanner;
import java.util.Arrays;
import java.lang.Math;
public class Main {
public static final int MOD = 26;
public static final int[] volume = new int[MOD << 1];
public static void main(String[] args) {
Scanner in = new Scanner(System.in);
while (in.hasNext()) {
String str = in.nextLine();
Arrays.fill(volume, -1);
for (int i = 0, len = str.length(); i < len; i++) {
char c = str.charAt(i);
int idx = c >= 'A' && c <= 'Z' ? MOD + c - 'A' : c - 'a';
if (volume[idx] == -1) {
volume[idx] = i;
System.out.printf("%c", c);
}
}
System.out.println();
}
in.close();
}
}
编辑于 2024-04-23 00:07:43
回复(0)
import java.util.Scanner;
// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
public static void main(String[] args) {
Scanner in = new Scanner(System.in);
while (in.hasNextLine()){
String str = in.nextLine();
String ret = Func(str);
System.out.println(ret);
}
}
public static String Func(String str) {
boolean[] arr = new boolean[58];
StringBuilder stringBuilder = new StringBuilder();
for (int i = 0; i < str.length(); i++) {
char ch = str.charAt(i);
if (arr[ch - 'A'] == false){
stringBuilder.append(ch);
arr[ch - 'A'] = true;
}
}
return stringBuilder.toString();
}
}
编辑于 2024-02-02 14:44:09
回复(0)
import java.util.Scanner;
// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
public static String func(String str){
boolean[] flags = new boolean[127];
StringBuilder stringBuilder = new StringBuilder();
for(int i = 0; i < str.length(); i++){
char ch = str.charAt(i);
if(!flags[ch]){
stringBuilder.append(ch);
flags[ch] = true;
}
}
return stringBuilder.toString();
}
public static void main(String[] args) {
Scanner in = new Scanner(System.in);
// 注意 hasNext 和 hasNextLine 的区别
while (in.hasNextLine()) { // 注意 while 处理多个 case
String str = in.nextLine();
String ret = func(str);
System.out.println(ret);
}
}
}
编辑于 2024-01-28 15:43:50
回复(0)
import java.util.Scanner;
// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
public static String func(String str){
boolean[] s = new boolean[128];
StringBuilder stringBuilder = new StringBuilder();
for(int i=0 ; i<str.length() ; i++){
char ch = str.charAt(i);
if(s[ch] == false){
stringBuilder.append(ch);
s[ch] = true;
}
}
return stringBuilder.toString();
}
public static void main(String[] args) {
Scanner in = new Scanner(System.in);
// 注意 hasNext 和 hasNextLine 的区别
while (in. hasNextLine()) { // 注意 while 处理多个 case
String str = in.nextLine();
String ret = func(str);
System.out.println(ret);
}
}
}
发表于 2023-11-22 16:10:20
回复(0)
import java.util.*;
// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
public static void main(String[] args) {
Scanner in = new Scanner(System.in);
// 注意 hasNext 和 hasNextLine 的区别
while (in.hasNextLine()) { // 注意 while 处理多个 case
Set<Character>set=new HashSet<>();
StringBuffer ans=new StringBuffer();
String a = in.nextLine();
int nu=0;
for(int i=0;i<a.length();i++){
char c=a.charAt(i);
if(set.contains(c))
continue;
else{
ans.append(c);
set.add(c);
}
}
System.out.println(ans.toString());
}
}
}
// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
public static void main(String[] args) {
Scanner in = new Scanner(System.in);
// 注意 hasNext 和 hasNextLine 的区别
while (in.hasNextLine()) { // 注意 while 处理多个 case
Set<Character>set=new HashSet<>();
StringBuffer ans=new StringBuffer();
String a = in.nextLine();
int nu=0;
for(int i=0;i<a.length();i++){
char c=a.charAt(i);
if(set.contains(c))
continue;
else{
ans.append(c);
set.add(c);
}
}
System.out.println(ans.toString());
}
}
}
发表于 2023-05-14 21:42:17
回复(0)
import java.util.*;
// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
public static void main(String[] args) {
Scanner in = new Scanner(System.in);
// 注意 hasNext 和 hasNextLine 的区别
while (in.hasNext()) { // 注意 while 处理多个 case
String a = in.nextLine();
//LinkedHashMap map = new LinkedHashMap();
String res = "";
for (int i = 0; i < a.length(); i++) {
char ch = a.charAt(i);
if(a.indexOf(ch) == i){
res += String.valueOf(ch);
}
}
System.out.println(res);
}
}
}
// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
public static void main(String[] args) {
Scanner in = new Scanner(System.in);
// 注意 hasNext 和 hasNextLine 的区别
while (in.hasNext()) { // 注意 while 处理多个 case
String a = in.nextLine();
//LinkedHashMap map = new LinkedHashMap();
String res = "";
for (int i = 0; i < a.length(); i++) {
char ch = a.charAt(i);
if(a.indexOf(ch) == i){
res += String.valueOf(ch);
}
}
System.out.println(res);
}
}
}
发表于 2023-02-21 16:53:57
回复(0)
public class Main {
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
while (scanner.hasNextLine()) {
String str = scanner.nextLine();
String str1 = func(str);
System.out.println(str1);
}
}
public static String func(String arr) {
boolean[] boo = new boolean[200];
StringBuilder sb = new StringBuilder();
int i = 0;
while (i < arr.length()) {
char a = arr.charAt(i);
if (boo[a] == false) {
boo[a] = true;
sb.append(a);
}
i++;
}
return sb.toString();
}
}
发表于 2022-12-12 21:17:51
回复(0)
import java.util.Scanner;
// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
public static void main(String[] args) {
Scanner read = new Scanner(System.in);
while(read.hasNext()){
int[] arr = new int[123];
String str = read.nextLine();
for(int i = 0;i < str.length();i++){
arr[str.charAt(i)] += 1;
}
int j = 0;
for(j = 0 ;j < str.length();j++){
if(arr[str.charAt(j)] != 0){
System.out.print(str.charAt(j));
arr[str.charAt(j)]=0;}
}
System.out.println();
}
}
}
发表于 2022-12-07 12:44:22
回复(0)
import java.util.*;
public class Main {
public static String fun(String s) {
StringBuilder sb=new StringBuilder();
for(int i=0;i<s.length();i++){
char ch=s.charAt(i);
if(!sb.toString().contains(ch+"")){
sb.append(ch);
}
}
return sb.toString();
}
public static void main(String[] args) {
Scanner scanner=new Scanner(System.in);
while(scanner.hasNextLine()){
String str1=scanner.nextLine();
String ret=fun(str1);
System.out.println(ret);
}
}
}
public class Main {
public static String fun(String s) {
StringBuilder sb=new StringBuilder();
for(int i=0;i<s.length();i++){
char ch=s.charAt(i);
if(!sb.toString().contains(ch+"")){
sb.append(ch);
}
}
return sb.toString();
}
public static void main(String[] args) {
Scanner scanner=new Scanner(System.in);
while(scanner.hasNextLine()){
String str1=scanner.nextLine();
String ret=fun(str1);
System.out.println(ret);
}
}
}
发表于 2022-09-12 21:57:04
回复(0)
import java.util.*;
public class Main{
public static String func(String str){
int[]array=new int[256];
StringBuilder sb=new StringBuilder();
for(int i=0;i<str.length();i++){
char ch=str.charAt(i);
if(array[ch]==0){
sb.append(ch);
array[str.charAt(i)]=1;
}
}
return sb.toString();
}
public static void main(String[] args){
Scanner scan=new Scanner(System.in);
while(scan.hasNextLine()){
String str=scan.nextLine();
String ret=func(str);
System.out.println(ret);
}
}
public class Main{
public static String func(String str){
int[]array=new int[256];
StringBuilder sb=new StringBuilder();
for(int i=0;i<str.length();i++){
char ch=str.charAt(i);
if(array[ch]==0){
sb.append(ch);
array[str.charAt(i)]=1;
}
}
return sb.toString();
}
public static void main(String[] args){
Scanner scan=new Scanner(System.in);
while(scan.hasNextLine()){
String str=scan.nextLine();
String ret=func(str);
System.out.println(ret);
}
}
}
思路（哈希值法）
1.写一个多组输入的代码
2.利用哈希值为零的特性，遍历整个数组，如果哈希值为0，则把该元素加到sb里面（利用append）（String不能修改，所以用StringBuilder或者StringBuffer创建一个新的sb对象），把这个第一次出现的哈希值改为1
3.这样所有出现过的元素都在sb里面（如果出现多次，因为已经把哈希值改为1，就不会加入到sb里面）
4.因为sb的类型是StringBuilder，所以需要利用同String方法重写
发表于 2022-04-21 20:44:49
回复(0)
import java.util.*;
public class Main{
public static StringBuffer func(String str) {
int[] array = new int[127];
StringBuffer str1=new StringBuffer();
for (int i = 0; i < str.length(); i++) {
if(array[str.charAt(i)]==0){
str1.append(str.charAt(i));
}
array[str.charAt(i)]++;
}
return str1;
}
public static void main(String[] args) {
Scanner scan = new Scanner(System.in);
while(scan.hasNextLine()) {
String str = scan.nextLine();
StringBuffer ret = func(str);
System.out.println(ret);
}
}
}
发表于 2022-04-20 23:09:54
回复(0)
麻烦大家看看这样为什么不通过，自测都可以但是就是通过不了
import java.util.*;
public class Main{
public static void main(String[] args){
Scanner sc = new Scanner(System.in);
String s = sc.next();
HashSet<Character> set = new HashSet<>();
ArrayList<Character> array = new ArrayList<>();
for(int i = 0; i < s.length();i++){
if(set.add(s.charAt(i))){
array.add(s.charAt(i));
}
}
for(int i = 0; i <array.size();i++){
System.out.print(array.get(i));
}
}
}
发表于 2022-03-23 17:28:22
回复(2)
import java.util.*;
public class Main{
public static void main(String[] args) {
Scanner in = new Scanner(System.in);
while (in.hasNextLine()) {
String str = in.nextLine();
//System.out.println(func1(str));
System.out.println(func2(str));
}
}
public static String func2(String str){
StringBuilder sb = new StringBuilder();
int[] arr = new int[58];
for (int i = 0; i < str.length(); i++) {
char ch = str.charAt(i);
if (arr[ch-65] == 0){
sb.append(ch);
arr[ch-65] = 1;
}
}
return sb.toString();
}
public static String func1(String str){
StringBuilder sb = new StringBuilder();
for (int i = 0; i < str.length(); i++) {
char ch = str.charAt(i);
if (!sb.toString().contains(ch+"")){
sb.append(ch);
}
}
return sb.toString();
}
}
public class Main{
public static void main(String[] args) {
Scanner in = new Scanner(System.in);
while (in.hasNextLine()) {
String str = in.nextLine();
//System.out.println(func1(str));
System.out.println(func2(str));
}
}
public static String func2(String str){
StringBuilder sb = new StringBuilder();
int[] arr = new int[58];
for (int i = 0; i < str.length(); i++) {
char ch = str.charAt(i);
if (arr[ch-65] == 0){
sb.append(ch);
arr[ch-65] = 1;
}
}
return sb.toString();
}
public static String func1(String str){
StringBuilder sb = new StringBuilder();
for (int i = 0; i < str.length(); i++) {
char ch = str.charAt(i);
if (!sb.toString().contains(ch+"")){
sb.append(ch);
}
}
return sb.toString();
}
}
发表于 2022-02-06 11:39:00
回复(0)
import java.util.*;
public class Main {
public static void main(String[] args) {
Scanner scan = new Scanner(System.in);
while(scan.hasNext()) {
String str = scan.nextLine();
StringBuilder sb = new StringBuilder();
for (int i = 0; i < str.length(); i++) {
char ch = str.charAt(i);
if (!sb.toString().contains(ch + "")) {
sb.append(ch);
}
}
System.out.println(sb.toString());
}
}
}
发表于 2021-11-04 10:26:55
回复(0)
import java.util.Scanner;
public class Main {
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
while (input.hasNext()) {
String str = input.nextLine();
if (null == str && str.length() > 100)
return;
//String str = "abcfacg";
String str2 = String.valueOf(str.charAt(0));
for (int i = 0; i < str.length(); i++) {
if (!str2.contains(String.valueOf(str.charAt(i))))
str2 += str.charAt(i);
}
System.out.println(str2);
}
input.close(); }
}
编辑于 2021-10-30 10:03:03
回复(0)
import java.util.*;
public class Main{
public static void main(String[] args){
Scanner scanner = new Scanner(System.in);
while(scanner.hasNext()){
String str = scanner.next();
StringBuilder sb = new StringBuilder();
for(int i=0;i<str.length();i++){
char ch = str.charAt(i);
if(!sb.toString().contains(ch+"")){
sb.append(ch);
}
}
System.out.println(sb);
}
}
}
public class Main{
public static void main(String[] args){
Scanner scanner = new Scanner(System.in);
while(scanner.hasNext()){
String str = scanner.next();
StringBuilder sb = new StringBuilder();
for(int i=0;i<str.length();i++){
char ch = str.charAt(i);
if(!sb.toString().contains(ch+"")){
sb.append(ch);
}
}
System.out.println(sb);
}
}
}
发表于 2021-06-06 10:49:41
回复(0)
import java.util.*;
public class Main{
public static void main(String[] args){
Scanner scan = new Scanner(System.in);
while(scan.hasNext()){
String str = scan.nextLine();
StringBuilder sb = new StringBuilder();
for(int i = 0;i <str.length();i++){
char ch = str.charAt(i);
if(!sb.toString().contains(ch+"")){
sb.append(ch);
}
}
System.out.println(sb);
}
}
}
发表于 2021-05-10 23:24:23
回复(0)
import java.util.*;
public class Main{
public static void main(String[] args){
Scanner sc = new Scanner(System.in);
while(sc.hasNextLine()){
String str = sc.nextLine();
Set<Character> keys = new HashSet<Character>();
for(int i=0; i<str.length();i++){
char v = str.charAt(i);
if(!keys.contains(v)){
System.out.print(v);
keys.add(v);
}
}
System.out.println("");
}
}
}
发表于 2020-02-11 13:06:15
回复(0)
import java.util.LinkedHashSet;
import java.util.Scanner;
import java.util.Set;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class Main
{
public static void main(String[] args)
{
Scanner sc=new Scanner(System.in);
while(sc.hasNext())
{
String str=sc.next();
String regex="^[A-Za-z]+$";
Matcher matcher=Pattern.compile(regex).matcher(str);
boolean flag=matcher.matches();
if(!flag||str.length()>100)
{
return;
}
Set<Character> set=new LinkedHashSet<>();
set.clear();
for(int i=0;i<str.length();i++)
{
char s=str.charAt(i);
set.add(s);
}
StringBuilder sb=new StringBuilder();
for(char s:set)
{
sb.append(""+s);
}
System.out.println(sb.toString());
}
}
}
发表于 2020-01-28 13:37:24
回复(0)
import java.util.*;
public class Main {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
while (sc.hasNext()) {
String next = sc.nextLine();
LinkedHashSet<Character> set = new LinkedHashSet<Character>();
char[] chars = next.toCharArray();
for (char aChar : chars) {
set.add(aChar);
}
for (char ch : set) {
System.out.print(ch);
}
System.out.println();
}
}
}
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
while (sc.hasNext()) {
String next = sc.nextLine();
LinkedHashSet<Character> set = new LinkedHashSet<Character>();
char[] chars = next.toCharArray();
for (char aChar : chars) {
set.add(aChar);
}
for (char ch : set) {
System.out.print(ch);
}
System.out.println();
}
}
}
编辑于 2018-09-22 10:42:48
回复(0)
问题信息
通过挑战的用户
查看代码-
2023-03-10 21:49:40 -
2023-03-10 16:14:45
-
2023-03-10 16:10:21
-
2023-03-07 16:25:31
-
2023-03-02 22:11:49
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