Discussion on Arrays: Left Rotation Challenge

rishabh10 3 years ago+ 2 comments

mine is also a brute force approach but it worked check it out if it helps you

import java.io.*;
import java.util.*;
import java.text.*;
import java.math.*;
import java.util.regex.*;

public class Solution {

    public static int[] arrayLeftRotation(int[] a, int n, int k) {
       int temp,i,j;
        for(i=0;i<k;i++){
            temp=a[0];
            for(j=1;j<n;j++){
               a[j-1]=a[j]; 
            }
            a[n-1]=temp;
        }
      
        return a;
    }
    
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int n = in.nextInt();
        int k = in.nextInt();
        int a[] = new int[n];
        for(int a_i=0; a_i < n; a_i++){
            a[a_i] = in.nextInt();
        }
      
        int[] output = new int[n];
        output = arrayLeftRotation(a, n, k);
        for(int i = 0; i < n; i++)
            System.out.print(output[i] + " ");
      
        System.out.println();
      
    }
}

pateldeep18 2 years ago+ 0 comments

int main(){
    int n; 
    int k; 
    int temp1, temp2;
    scanf("%d %d",&n,&k);
    
    int *a = malloc(sizeof(int) * n);
    for(int a_i = 0; a_i < n; a_i++){
       scanf("%d",&a[a_i]);
    }
    k = k %n;
    for(int a_i = 0; a_i < k; a_i++){
        temp1 = a[0];
        for(int i = 1; i < n; i++){
            a[i-1] = a[i];
        }
        a[n-1] = temp1;
    }

    for(int a_i = 0; a_i < n; a_i++){
       printf("%d ", a[a_i]);
    }
    
    return 0;
}

my code is the same as yours but i still time in test case 8, why is that?

not_nigel 2 years ago+ 0 comments

You're not wrong but this solution is inefficient. You're solving it in O(((n-1) * k) + 2n). The solution below is in O(2n).

private static void solution(int size, int shift, int[] arr) {

		int count = 0;

		for (int i = shift; i < size; i++) {
			System.out.print(arr[i]);
			System.out.print(" ");
			count++;
		}

		count = 0;

		for (int i = size - shift; i < size; i++) {
			System.out.print(arr[count]);
			if (i != size - 1)
				System.out.print(" ");
			count++;
		}
	}