Left Rotate Array by K Positions

Code

#include <stdio.h>

void reverse(int arr[], int n) {
    for(int i=0;i<n/2;i++) {
        arr[i]+=arr[(n-1)-i];
        arr[(n-1)-i]=arr[i]-arr[(n-1)-i];
        arr[i]-=arr[(n-1)-i];
    }
}
// 1 2 3 4 5
// 2 1 3 4 5
// 
void rotate_left(int arr[], int n, int k) {
    k=k%(n);
    // reverse k
    reverse(arr, k);
    reverse((arr+k),n-k);
    reverse(arr, n);
}

int main() {
    int n, k;
    scanf("%d %d", &n, &k);

    int arr[100];

    // Read array elements
    for (int i = 0; i < n; i++) {
        scanf("%d", &arr[i]);
    }

    // Rotate the array
    rotate_left(arr, n, k);

    // Print the rotated array
    for (int i = 0; i < n; i++) {
        printf("%d", arr[i]);
        if(i < n-1){
        	printf(" ");
        }
    }

    return 0;
}

Solving Approach

 

 

 

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Input

5 2 1 2 3 4 5

Expected Output

3 4 5 1 2