nowcoder updating……

牛客链接

例：输入：abcqweracb
输出：abcqwer

• 使用StringBuilder，把出现过的字符append拼接
• 数组，对应下标，没有出现的为0，出现过置为1

import java.util.Scanner;

public class Main {
    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 static String func(String str) {
        StringBuilder sb = new StringBuilder();
        int[] array = new int[127];
        // int[] array = new int[58];
        for(int i = 0; i < str.length(); i++) {
            char ch = str.charAt(i);
            if(array[ch] == 0) {
            // if(array[ch-65] == 0) {
                sb.append(ch);
                array[ch] = 1;
                // array[ch-65] = 1;
            }
        }
        return sb.toString();
    }
    
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        while(scanner.hasNextLine()) {
            String str = scanner.nextLine();
            String ret = func(str);
            System.out.println(ret);
        }
    }
}