HACKERRANK SOLUTIONS - INTERVIEW PREPARATION KIT - ARRAY - IN C++

  HACKERRANK SOLUTIONS - INTERVIEW PREPARATION KIT - IN C++

ARRAY

1. 2D ARRAY DS

https://www.hackerrank.com/challenges/2d-array/problem?h_l=interview&playlist_slugs%5B%5D%5B%5D=interview-preparation-kit&playlist_slugs%5B%5D%5B%5D=arrays

min sum = -9*7 as there are 7 values in 1 hourglass

int hourglassSum(vector<vector<int>> arr) {

    int row = arr.size();

    int col = arr[0].size();

    int max_sum = -63, sum = 0;

    for(int i = 0; i < row-2; i++){

        for(int j = 0; j < col-2; j++){

            sum = arr[i][j] + arr[i][j+1] + 

                arr[i][j+2] + arr[i+1][j+1] + 

                arr[i+2][j] + arr[i+2][j+1] + 

                arr[i+2][j+2];

            if(sum > max_sum)

                max_sum = sum;

        }

    }

    return max_sum;

}

2. LEFT ROTATION

https://www.hackerrank.com/challenges/ctci-array-left-rotation/problem?h_l=interview&playlist_slugs%5B%5D%5B%5D=interview-preparation-kit&playlist_slugs%5B%5D%5B%5D=arrays

vector<int> rotLeft(vector<int> a, int d) {

    for(int j = 0; j < d; j++){

        //rotate left by 1

        int temp = a[0];

        int n = a.size();

        for(int i = 0; i < n-1; i++){

            a[i] = a[i+1];

        }

        a[n-1] = temp;

    }

    return a;

}