我想使用遞歸檢查一個整數在數組中是否唯一

Question

//移除方法

public static int[] remove(int[]a){
int [] x = new int[a.length - 1];

for(int i = 1; i <= x.length; i++) {
    x[i-1] = a[i];  
}

return x;}

IsUniqueMethod 檢查 Passed int 的唯一性

public static boolean isUnique(int []x, int n) {
if(x.length == 1) { 
    return true;}
else {
    
    if(x[0] != n) {
        return isUnique(remove(x), n);
    }
    else {
    return false;
    }
    
}

}

我如何檢查唯一性？

Answer 1

這永遠不會為您提供您正在尋找的 isUnique() 輸出。 即使您以某種方式使其通過了 ArrayIndexOutOfBound，您編寫的代碼也非常低效，以至於每次您在遞歸調用中傳遞方法參數時都會調用 JIT。

試試這個

import java.util.ArrayList;
import java.util.Scanner;

public class Unique {

     private static Scanner sc;

     public static void main(String[] args) {

         sc = new Scanner(System.in);

         //Taking length of the array from the user
         System.out.println("Enter the length of the desired array : ");
         int length = sc.nextInt();

         System.out.println("Please enter the values of the array");
         ArrayList<Integer> al = new ArrayList<Integer>();

         //Entering the values into the arrayList
         for (int i = 0; i < length; i++) {
             al.add(sc.nextInt());
         }

         System.out.println("Enter a number you wish to check : ");
         int checkNumber = sc.nextInt();

         //Using the built-in method indexOf() to check the occurance of the entered number and return its index if present, else returns -1
         System.out.println(al.indexOf(checkNumber)>=0?"The entered number is present in the array":"The entered number is not present in the array");

     }}