Miscellaneous on Data Structures
practice.

What is the output of the following code?

#include<stdio.h>
int recursive_sum(int n)
{
      if(n == 0)
        return 0;
      return n + recursive_sum(n - 1);
}
int main()
{
     int n = -4;
     int ans = recursive_sum(n);
     printf("%d",ans);
     return 0;
}

Consider the fleury's algorithm given below. Which of the following best suits the blank?

Graph must have 0 or 2 odd vertices  
if there are 0 odd vertices, start from any vertex 
if there are 2 odd vertices, start from any one of them 
follow any of the edge, always choose the ______________  
repeat for all the edges of the graph

Vertex coloring and chromatic number are one and the same.

What is the output of the following code?

#include<stdio.h>
int recursive_sum(int n)
{
      if(n == 0)
        return 0;
      return n + recursive_sum(n - 1);
}
int main()
{
     int n = 0;
     int ans = recursive_sum(n);
     printf("%d",ans);
     return 0;
}

Which algorithm can be used to find an eulerian cycle in a graph?

What is the time complexity of Heap's algorithm?

What will be the plain text corresponding to cipher text "RSEADC" if with the number of columns are given to be 3 and route of reading is down the columns?

What will be the encrypted text corresponding to plain text "EXAMPLE" using columnar transposition cipher with the keyword as "INDIA"?

What will be the slope of the line given by 10x + 5y + 8=0?

How many partitions will be formed for the integer 3?

Which cipher is represented by the following function?

public class Cipher
{
    public static String encrypt(String text, final String key)
    {
        String res = "";
        text = text.toUpperCase();
        for (int i = 0, j = 0; i < text.length(); i++)
        {
            char c = text.charAt(i);
            if (c < 'A' || c > 'Z')
                continue;
            res += (char) ((c + key.charAt(j) - 2 * 'A') % 26 + 'A');
            j = ++j % key.length();
        }
        return res;
    }

How many times is the function recursive_binary_search() called when the following code is executed?

#include<stdio.h>
int recursive_binary_search(int *arr, int num, int lo, int hi)
{
      if(lo > hi)
       return -1;
      int mid = (lo + hi)/2;
      if(arr[mid] == num)
        return mid;
      else if(arr[mid] < num)
          lo = mid + 1;
      else
          hi = mid - 1;
      return recursive_binary_search(arr, num, lo, hi);
}
int main()
{
      int arr[5] = {1,2,3,4,5},num = 1,len = 5;
      int indx = recursive_binary_search(arr,num,0,len-1);
      printf("Index of %d is %d",num,indx);
      return 0;
}

What is the period in bifid cipher?

An optimal solution satisfying men's preferences is said to be?

Which is the correct term of the given relation, lcm (a, b) * gcd (a, b) =?

The cost required to execute a FIFO algorithm is expensive.

The problem of placing n queens in a chessboard such that no two queens attack each other is called as?

What is the time complexity of the following recursive implementation used to find the largest and the smallest element in an array?

#include<stdio.h>
int max_of_two(int a, int b)
{
      if(a > b)
        return a;
      return b;
}
int min_of_two(int a, int b)
{
      if(a < b)
        return a;
      return b;
}
int recursive_max_element(int *arr, int len, int idx)
{
      if(idx == len - 1)
      return arr[idx];
      return max_of_two(arr[idx], recursive_max_element(arr, len, idx + 1));
}
int recursive_min_element(int *arr, int len, int idx)
{
      if(idx == len - 1)
      return arr[idx];
      return min_of_two(arr[idx], recursive_min_element(arr, len, idx + 1));
}
int main()
{
    int n = 10, idx = 0, arr[] = {5,2,6,7,8,9,3,-1,1,10};
    int max_element = recursive_max_element(arr,n,idx);
    int min_element = recursive_min_element(arr,n,idx);
    printf("%d %d",max_element,min_element);
    return 0;
}

What is the formula used for decoding the ciphered text using affine cipher(a,b are constants and x is the numerical equivalent of a letter to be encrypted)?

What is the time complexity of the following recursive implementation to find the nth fibonacci number?

int fibo(int n)
{
     if(n == 1)
        return 0;
     else if(n == 2)
        return 1;
     return fibo(n - 1) + fibo(n - 2);
}
int main()
{
     int n = 5;
     int ans = fibo(n);
     printf("%d",ans);
     return 0;
}