Luxsoft Interview questions

 Find the Normal of a square matrix =  Sqrt (sum of squares of all elements of the matrix )

[ 1 2 3]

[ 2 3 4]

[ 400000 500000 6]

[ 1 2 3 2 3 4 4 5 6 ]

double find_normal_square_matrix(int arr[][],int num)

{

  long long sum=0;

  int k=0;

   for(i=0; i< num*num; i++)

   {

       int j= i%num;

       if(i%num == 0)

    { j = 0;

  k++;

}

        temp = arr[k][j];

        sum+=(long long)temp*temp;

   }

   return sqrt(sum);

}

Write a simple C++ program to delete a node in the single linked list when the pointer to the node is given as input (no other) )with all scenarios considered

iferoz@luxoft.com

Solution:- copy all the next nodes data to itself and delete the last node

void node_del(struct node* ptr)

{

   if(ptr->next == NULL)

   {

     free(ptr);

return;

   }

  struct node* t = ptr->next;

  ptr->data = t->data;

  ptr->next = t->next;

  free(t);

}

What will happen to the second last node if last node gets deleted ?

Ans:- will the second last node's next become a dangling pointer ! Yes

How to solve the dangling pointer issue ?

Write a C++ program for finding maximal subarray given an array as input. The input is an array & its size and the o/p of the program will be 2 indices - lower and upper index between which is the max sub array is present.  

E.g. 

 

A[10] = { 1, -4, -1, 3, 4, 5, -17, 8, 1,2 }

 

Here the max subarray is { 3, 4, 5} ans: 3, 5 (indices)

 

E.g 2

 

A[10] = { 1, -4, -1, 3, 4, 5, -7, 8, 1,2 }

 

Here the max subarray is {3, 4, 5, -7, 8, 1,2 } ans: 3, 9 (indices)

 

Please handle all scenarios / cases… and print the array also

int max_subarray(int arr[], int size)

{

  int max_1 = 0, max_2 = -60000;

  for(int i=0; i<size; i++)

  {

    max_1 = max_1 + arr[i];

if(  max_1 < arr[i] )

{   max_1 = arr[i];

     begin = i;

}

if(max_2 < max_1)

{

  max_2 = max_1;

  start_index= begin;

  final_index =i;

}

  }

  for(i=start_index; i<final_index; i++)

    printf("%d ", arr[i]);

  return max_2;

}