Java2022期末作业

约 113 个字 69 行代码 预计阅读时间 1 分钟

Problem 1

Define a Java method to print the number of vowel character and the number of spaces in a given string.

Vowels include a,A,e,E,i,I,o,O,u,U.

code

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.concurrent.LinkedTransferQueue;

public class java2022 {
    public static void main(String[] args) {
        System.out.println(count("loveislove1 "))
    }

    public static int count(String str){
        int tab = 0;
        int vowel = 0;
        for(int i = 0;i<str.length();i++){
            char letter = str.charAt(i);
            switch (letter) {
                case 'a', 'e', 'i', 'o', 'u', 'A', 'E', 'I', 'O', 'U' -> vowel += 1;
            }
            if (letter == ' ') {
                tab += 1;
            }
        }
        return tab;
    }

description

i defined a function which called count.First we using the String.charAt() method to traverse the whole string.Then use switch to judge if this is a vowel character.

Problem 2

Define a method to collect the common elements in two arrays of integers. int[] getCommonElements(int[] arr1, int[] arr2)

code

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.concurrent.LinkedTransferQueue;

public class java2022 {
    public static void main(String[] args) {
        int[] arr1 = {2,1,3,4,56};
        int[] arr2 = {3,4,5};
        System.out.println(Arrays.toString(getCommonElements2(arr1,arr2)));
    }


    public static int[] getCommonElements(int[] arr1, int[] arr2){
        int maxlength = Math.max(arr1.length,arr2.length);
        int arr[] = new int[maxlength];
        int k = 0;
        for(int i = 0;i<arr1.length;i++){
            for(int j = 0;j<arr2.length;j++){
                if(arr1[i] == arr2[j]){
                    arr[k++] = arr1[i];
                    break;
                }
            }
        }
        return arr;
    }

    public static int[] getCommonElements2(int[] arr1, int[] arr2){
        int maxlength = Math.max(arr1.length,arr2.length);
        int arr[] = new int[maxlength];
        int k = 0;
        Arrays.sort(arr1);
        for(int i = 0;i<arr1.length;i++){
            if(Arrays.binarySearch(arr2,arr1[i])>-1){
                arr[k++] = arr1[i];
            }
        }
//        //System.out.println(arr[]);
//        System.out.println(Arrays.binarySearch(arr2,arr1[3]));
        return arr;
    }
}

description

in the problem i define two methods:one is the most common,the other use the Java Array static method binarySearch and sort.