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Practice #3

Lesson 12 of 14 in Coddy's Doubly Linked List - Data Structures Series #6 course.

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Challenge

Easy

Write a function rotateRight that gets an integer array arr (the values of a doubly linked list) and an integer k, and returns the array rotated right by k positions.

If k is larger than the length, only the remainder matters (rotating by n brings you back to where you started). If the list is empty, return an empty array.

Use a doubly linked list to solve this problem!

You must use the DoublyLinkedList class (provided in doublylinkedlist.<ext> along with node.<ext>) — do not use language built-ins like arrays' reverse, slicing, sort, or stdlib list operations to compute the result.

Try it yourself

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "solution.h"

int main() {
    char line1[8192];
    char line2[64];
    if (!fgets(line1, sizeof(line1), stdin)) line1[0] = '\0';
    if (!fgets(line2, sizeof(line2), stdin)) line2[0] = '\0';
    int arr[4096];
    int len = 0;
    char* tok = strtok(line1, " \t\r\n");
    while (tok) { arr[len++] = atoi(tok); tok = strtok(NULL, " \t\r\n"); }
    int n = atoi(line2);
    int rs = 0;
    int* r = rotateRight(arr, len, n, &rs);
    for (int idx = 0; idx < rs; idx++) {
        if (idx > 0) printf(" ");
        printf("%d", r[idx]);
    }
    printf("\n");
    return 0;
}

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