//exercise 6.1package second;import java.util.Scanner;public class first {    /**     * @param args     */    public static void main(String[] args) {        // TODO Auto-generated method stub        Scanner in=new Scanner(System.in);        System.out.print("Enter the number of students:");        int number=in.nextInt();        System.out.print("Enter "+number+" scores:");        int []score=new int[number];        getscores(score);        int best=max(score);        for(int i=0;i<number;i++){            System.out.println("Student "+i+" score is "+score[i]+" and grade is "+                    grade(score[i],best));        }            }        public static void getscores(int []score){        Scanner in=new Scanner(System.in);        for(int i=0;i<score.length;i++){            score[i]=in.nextInt();        }    }        public static int max(int[] score){        int max=score[0];        for(int i=0;i<score.length;i++){            if(max<score[i])                max=score[i];        }        return max;    }        public static char grade(int score,int max){        if(score>=max-10)            return ‘A‘;        else if(score>=max-20)            return     ‘B‘;        else if(score>=max-30)            return ‘C‘;        else if(score>=max-40)            return ‘D‘;        else            return ‘F‘;    }}//exercise 6.2package second;import java.util.Scanner;public class second {    /**     * @param args     */    public static void main(String[] args) {        // TODO Auto-generated method stub        int []number=get();        reverseprint(number);    }        public static int[] get(){        Scanner in=new Scanner(System.in);        int[] number=new int[10];        System.out.println("input 10 number:");        for(int i=0;i<number.length;i++){            number[i]=in.nextInt();        }        return number;    }        public static void reverseprint(int[]Array){        for(int i=Array.length-1;i>=0;i--){            System.out.print(Array[i]+" ");        }    }}//exercise 6.3package second;import java.util.Scanner;public class third {    /**     * @param args     */    public static void main(String[] args) {        // TODO Auto-generated method stub        Scanner in=new Scanner(System.in);        int[] newarray=new int[100];        int temp;                for(int i=0;i<newarray.length;i++){            newarray[i]=0;        }        System.out.print("Enter the integers between 1 and 100：");        while((temp=in.nextInt())!=0){            newarray[temp]++;        }                resultprint(newarray);    }        public static void resultprint(int []array){        for(int i=0;i<array.length;i++){            if(array[i]==1)                System.out.println(i+" occurs "+array[i]+" time");            if(array[i]!=0&&array[i]!=1)                System.out.println(i+" occurs "+array[i]+" times");        }    }}//exercise 6-4package first;import java.util.Scanner;public class first {    /**     * @param args     */    public static void main(String[] args) {        // TODO Auto-generated method stub        Scanner in=new Scanner(System.in);        int []score=new int[100];        int i=0,sum=0,count=0;        System.out.print("input integer:");        while((score[i]=in.nextInt())!=-1){            sum+=score[i++];            count++;        }        int average=sum/count;        int big=0,small=0;        for(int j=0;j<count;j++){            if(score[j]<average)                small++;            else                big++;        }        System.out.println("average is "+average);        System.out.println("better than average is "+big);        System.out.println("small than average is "+small);    }}//exercise 6-5package first;import java.util.Scanner;public class second {    /**     * @param args     */    public static void main(String[] args) {        // TODO Auto-generated method stub        Scanner in=new Scanner(System.in);        System.out.print("Enter ten numbers:");        int []integer=new int[10];        int count=0;                for(int i=0;i<10;i++){            boolean judge=false;            int temp=in.nextInt();            for(int j=0;j<count;j++){                if(temp==integer[j]){                    judge=true;                }            }            if(!judge){                integer[count++]=temp;            }        }        System.out.print("input integer:");        for(int i=0;i<count;i++){            System.out.print(integer[i]+" ");        }    }}//exercise 6-7package first;public class third {    /**     * @param args     */    public static void main(String[] args) {        // TODO Auto-generated method stub        int []counts=new int[10];        for(int i=0;i<100;i++){            int random=(int)(Math.random()*10);            counts[random]++;        }        for(int i=0;i<10;i++){            System.out.print(i+" ");        }        System.out.println();        for(int i=0;i<10;i++){            System.out.print(counts[i]+" ");        }    }}//exercise 6-8package first;public class fourth {    /**     * @param args     */    public static int average(int[]array){        int sum=0,count=0;        for(int i=0;i<array.length;i++){            sum+=array[i];            count++;        }        return sum/count;    }    public static double average(double []array){        double sum=0;        int count=0;        for(int i=0;i<array.length;i++){            sum+=array[i];            count++;        }        return sum/count;    }}//exercise 6-9package first;public class fifth {    /**     * @param args     */    public static double min(double []array){        double min=array[0];        for(int i=0;i<array.length;i++){            if(min>array[i])                min=array[i];        }        return min;    }    }//exercise 6-10package first;public class seventh {    /**     * @param args     */    public static int indexOfSmallestElement(double[] array){        double min=array[0];        for(int i=0;i<array.length;i++){            if(min>array[i])                min=array[i];        }        for(int i=0;i<array.length;i++){            if(min==array[i])                return i;        }        return 0;    }}