程序设计大赛编程题练习

package com.n;

public class Letter {
    private String word;
    private int times;
    public Letter( ){
        
    }
    public Letter(String word,int times2){
        this.word=word;
        this.times=times2;
    }
    public String getWord() {
        return word;
    }
    public void setWord(String word) {
        this.word = word;
    }
    public int getTimes() {
        return times;
    }
    public void setTimes(int times) {
        this.times = times;
    }
    
    
}

package com.n;


/*第一题:10个评委评分，除掉最高分和最低分，计算最后选手的平均分。
第二题:
题目描述：请编写程序，从包含大量单词的文本中删除出现次数最少的单词。如果有多个单词都出现最少的次数，则将这些单词都删除。  
评分标准：程序输出结果必须正确，内存使用越少越好，程序的执行时间越快越好。 

hello  world  world nihao xyz hello hello  nihao 

String info = "hello  world  world nihao xyz hello hello  nihao 你好";

1 知道这个字符串里面有多少个单词  hello world  nihao  xyz
  String s[] = info.split(" ");
2 知道每个单词出现的次数
   hello 3 
   world 2 
   nihao 2
   xyz 1
3  info.replaceAll("xyz","");
4  String StringBuilder 
*/
public class First {
    public static void main(String[] args) {
        String s = "hello world world nihao xyz hello hello nihao";
        System.out.println("替换之前的字符串是："+s);
        // 一共有多少个单词
        String[] ss = s.split(" ");
        System.out.println("单词的个数是：" + ss.length);
        String[] words = new String[ss.length];// 极端情况，每个单词只出现一次
        words[0] = ss[0];
        int count = 1;// 记录words数组中有多少个非空元素，即不同的单词个数
        for (int i = 1; i < ss.length; i++) {
            int j = 0;
            for (; j < count; j++) {// 取出words中的每一个单词
                if (words[j].equals(ss[i])) {
                    break;
                }
            }
            if (j==count) {//说明在words中没找到该单词
                words[j]=ss[i];
                count++;
            }
        }
        System.out.println("不同的单词如下：");
        for (int i = 0; i < count; i++) {
            System.out.print(words[i]+" ");
        }
        System.out.println();
        Letter[] letters=new Letter[count];
        for (int i = 0; i < count; i++) {
            int times=0;
            int index=0;
            while(true){
                index=s.indexOf(words[i],index);
                if (index==-1) {
                    break;
                }else{
                        times++;
                        index=s.indexOf(words[i],index)+words[i].length();
                }
            }
            Letter letter=new Letter(words[i],times);
            letters[i]=letter;
        }
        for (Letter letter : letters) {
            System.out.println(letter.getWord()+" "+letter.getTimes());
        }
        
        
        
        int min=letters[0].getTimes();
        for (Letter letter : letters) {
            if (letter.getTimes()<min) {
                min=letter.getTimes();
            }
        }
        System.out.println("min="+min);
        
        //第一方法：
/*        String s1=null;
        for (Letter letter : letters) {
            if (letter.getTimes()==min) {
                s1=s.replaceAll(letter.getWord()+"", "");
            }
        }
        System.out.println("替换完的字符串是："+s1);
*/
        //第二方法：
        for (int i=0;i<count;i++) {
            if (letters[i].getTimes()==min) {
                if (i==(count-1)) {
                    s=s.replaceAll(letters[i].getWord(),"");
                }else{
                    s=s.replaceAll(letters[i].getWord()+"", "");
                }
            }
        }
        System.out.println("替换完的字符串是："+s);    
    
    }

}