题解 | #删除字符串中出现次数最少的字符#

本题主要考校map的枚举Iterator和特定方法getOrDefault的使用

public class Main{
    public static void main(String[] args){
        Scanner in = new Scanner(System.in);
        HashMap<Character,Integer> map = new HashMap<Character,Integer>();
        String s = in.nextLine();
        StringBuffer sb = new StringBuffer();
        int min = Integer.MAX_VALUE;
        for(char ch : s.toCharArray()){
            map.put(ch,map.getOrDefault(ch,0)+1);
        }
        //获取最小的那个次数-min
        Iterator<Map.Entry<Character,Integer>> it = map.entrySet().iterator();
        while(it.hasNext()){
            Map.Entry<Character,Integer> entry = it.next();
            min = Math.min(min,entry.getValue());
        }
        //排序-删除
        for(int i = 0; i < s.length(); i++){
            if(map.containsValue(min)){
                if(map.get(s.charAt(i)) == min){
                    sb.append("");
                    continue;
                }else{
                    sb.append(s.charAt(i));
                }
            }
         
        }
        System.out.println(sb.toString());
    }
}