Java 删除字符串中出现次数最少的字符

 

 

方法一

import java.util.HashMap;
import java.util.Map;
import java.util.Scanner;

public class Main{
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        while(sc.hasNext()) {
            String dis = del(sc.nextLine());
            System.out.println(dis);
        }
    }
    
    public static String del(String str) {
        //统计字符出现的次数
        Map<Character, Integer> map = new HashMap<>();
        for(char c: str.toCharArray()) {
            if (map.containsKey(c)) {
                map.put(c, map.get(c) +1);
            } else {
                map.put(c, 1);
            }
        }
        //遍历记录最小出现次数
        int min = Integer.MAX_VALUE;
        for (Map.Entry<Character, Integer> entry: map.entrySet()) {
            if(entry.getValue() < min) {
                min = entry.getValue();
            }
        } 
        
        //删除字符
        for (Map.Entry<Character, Integer> entry: map.entrySet()) {
            if (entry.getValue() == min) {
                str = str.replace(entry.getKey() + "", "");
            }
        }
        return str;
    }
}

 

方法二

import java.io.*;


public class Main{
    
    public static void main(String[] args) throws IOException{
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        String str = null;
        StringBuilder  sb = new StringBuilder();
        while((str = br.readLine()) != null){
            char[] chArr = str.toCharArray();
            int[] countArr = new int[chArr.length];
            //统计每一位上字符在整个字符串中出现的次数
            for(int i=0;i< chArr.length ;i++){
                for(int j = 0; j<chArr.length;j++){
                    if(chArr[i] == chArr[j]){
                        countArr[i] += 1;
                    }
                }
            }
            
            //假设第一位字符对应的次数最小，能找到更小的则替换
            int min = countArr[0];
            for(int id : countArr){
                if(id < min){
                    min = id;
                }
            }
            
            //遍历countArr中字符出现次数，不等于最小的则将对应字符添加到sb中
            for(int i = 0;i< countArr.length;i++){
                if(countArr[i] != min){
                    sb.append(chArr[i]);
                }
            }
            sb.append("\n");
        }
        System.out.print(sb.toString());
    }
}