Java语言程序设计第七版第七章课后习题

7.1 指定学生成绩等级

import java.util.Scanner;

public class 数组 {

	public static void main(String[] args) {
		// TODO Auto-generated method stub

		Scanner input = new Scanner(System.in);
		System.out.print("Enter the number of students:");
		int number = input.nextInt();
		int[] myList = new int[number];
		System.out.print("Enter " + number + " 4scores");
		for (int i = 0; i < myList.length; i++) {
			myList[i] = input.nextInt();
		}
		double best = myList[0];
		for (int i = 0; i < number; i++) {
			if (myList[i] > best)
				best = myList[i];
		}
		for (int i = 0; i < number; i++) {
			if (myList[i] >= best - 10)
				System.out.println("Student " + i + "score is " + myList[i] + " and grade is A");
			else if (myList[i] >= best - 20)
				System.out.println("Student " + i + "score is " + myList[i] + " and grade is B");
			else if (myList[i] >= best - 30)
				System.out.println("Student " + i + "score is " + myList[i] + " and grade is C");
			else if (myList[i] >= best - 40)
				System.out.println("Student " + i + "score is " + myList[i] + " and grade is D");
			else
				System.out.println("Student " + i + "score is " + myList[i] + " and grade is F");
		}
	}

}

7.3
import java.util.Arrays;
import java.util.Scanner;

public class 数字出现顺序 {

public static void main(String[] args) {

	// TODO Auto-generated method stub

	Scanner input = new Scanner(System.in);

	System.out.println("Enter the integers between 1 and 100");
	int[] a = new int[100];

	int count = 0;

	while (true) {

		int temp = input.nextInt();

		if (temp == 0)

			break;

		a[count] = temp;

		count++;

	}

	Arrays.sort(a, 0, count);

	int time;

	for (int i = 0; i < count; i++) {
		time = 1;
		for (int j = i + 1; j < count; j++) {

			if (a[i] == a[j] && a[j] != 0) {

				time++;
				a[j] = 0;
			}

		}
		if (a[i] != 0)
			System.out.println(a[i] + " occurs " + time + (time > 1 ? " times" : " time"));

	}

}

}