Given an array arr[] of integers and another integer D, the task is to perform D circular rotations on the array and print the modified array. Examples:
Input: Arr[] = {1, 2, 3, 4, 5, 6}, D = 2 Output: 5 6 1 2 3 4 Input: Arr[] = {1, 2, 3}, D = 2 Output: 2 3 1
Approach: Using Deque in C++, a rotation can be performed deleting the last element from the deque and inserting it at the beginning of the same deque. Similarly, all the required rotations can be performed and then print the contents of the modified deque to get the required rotated array. If the number of rotations is more than the size of the deque then just take the mod with N, So, D = D%N. Where D is the number of rotations and N is the size of the deque. Below is the implementation of the above approach:
CPP
// C++ implementation of the approach #include <bits/stdc++.h> using namespace std; // Function to circular rotate // the array by d elements void rotate(deque<int> deq, int d, int n) { // Push first d elements // from last to the beginning for (int i = 0; i < d; i++) { int val = deq.back(); deq.pop_back(); deq.push_front(val); } // Print the rotated array for (int i = 0; i < n; i++) { cout << deq[i] << " "; } cout << endl; } // Driver code int main() { deque<int> v = { 1, 2, 3, 4, 5, 6, 7 }; int n = v.size(); int d = 5; rotate(v, d % n, n); } |
3 4 5 6 7 1 2
Time Complexity: O(n)
Auxiliary Space: O(n)
Ready to dive in? Explore our Free Demo Content and join our DSA course, trusted by over 100,000 neveropen!
