Miscellaneous on Data Structures
practice.

Hill cipher is an example of . . . . . . . .

What is the running time of naive matrix multiplication algorithm?

Encryption in running key cipher is done using . . . . . . . .

Which of the following gives the value for Ø(180)?

You have to find the sum of digits of a number given that the number is always greater than 0. Which of the following base cases can replace the base case for the below code?

#include<stdio.h>
int recursive_sum_of_digits(int n)
{
      if(n == 0)
        return 0;
      return n % 10 + recursive_sum_of_digits(n/10);
}
int main()
{
      int n = 1201;
      int ans = recursive_sum_of_digits(n);
      printf("%d",ans);
      return 0;
}

Which of the following cipher is formed by applying columnar transposition cipher twice?

Placing n-queens so that no two queens attack each other is called?

What is the purpose of using square root decomposition?

What is the message length 'k' of a Hamming(7,4) code?

What will be the time complexity of the following code?

#include <stdio.h> 
#include <math.h> 
void PowerSet(char *set, int set_size) 
{ 
	unsigned int pow_size = pow(2, set_size); 
	int count, j; 	
	for(count = 0; count < pow_size; count++) 
	{ 
	     for(j = 0; j < set_size; j++) 
	     { 
 
		if(count & (1<<j)) 
			printf("%c", set[j]); 
	     } 
	     printf(","); 
	} 
} 
int main() 
{ 
	char strset[] = {'a','b','c'}; 
	PowerSet(strset, 3); 
	return 0; 
}

. . . . . . . . is a family of combinatorial optimization problems in which a graph is partitioned into two or more parts with constraints.

Which of the following graphs don't have chromatin number less than or equal to 2?

Fractional knapsack problem can be solved in time O(n).

Which of the following best represents the time complexity to access an item in the least recently used cache?

What will be the worst case time complexity of finding the sum of elements in a given range of (l,r) in an array of size n when we use square root optimization?

Function rand() generates unique random numbers every time.

What will be output for the given code?

#include<bits/stdc++.h> 
using namespace std; 
string encrypter(string keyword) 
{ 
	string encoded = ""; 	
	bool arr[26] = {0}; 
	for (int i=0; i<keyword.size(); i++) 
	{ 
		if(keyword[i] >= 'A' && keyword[i] <= 'Z') 
		{ 		
			if (arr[keyword[i]-65] == 0) 
			{ 
				encoded += keyword[i]; 
				arr[keyword[i]-65] = 1; 
			} 
		} 
		else if (keyword[i] >= 'a' && keyword[i] <= 'z') 
		{ 
			if (arr[keyword[i]-97] == 0) 
			{ 
				encoded += keyword[i] - 32; 
				alpha[keyword[i]-97] = 1; 
			} 
		} 
	} 
	for (int i=0; i<26; i++) 
	{ 
		if(arr[i] == 0) 
		{ 
			arr[i]=1; 
			encoded += char(i + 65); 
		} 
	} 
	return encoded; 
} 
string ciphertxt(string msg, string encoded) 
{ 
	string cipher=""; 
	for (int i=0; i<msg.size(); i++) 
	{ 
		if (msg[i] >='a' && msg[i] <='z') 
		{ 
			int pos = msg[i] - 97; 
			cipher += encoded[pos]; 
		} 
		else if (msg[i] >='A' && msg[i] <='Z') 
		{ 
			int pos = msg[i] - 65; 
			cipher += encoded[pos]; 
		} 
		else
		{ 
			cipher += msg[i]; 
		} 
	} 
	return cipher; 
} 
int main() 
{ 
	string keyword; 
	keyword = "cipher"; 	
	string encoded = encrypter(keyword); 
	string message = "hello"; 
	cout  << ciphertxt(message,encoded) << endl; 
	return 0; 
}

What is the set partition problem?

Find the output of the following code.

#include<math.h> 
#include<iostream.h>
using namespace std;
void distance(float x, float y, float a, float b, float c) 
{ 
	float d = fabs((a * x + b * y + c)) / (sqrt(a * a + b * b)); 
	cout<<d;
	return; 
} 
int main() 
{ 
	float x = -2; 
	float y = -3; 
	float a = 5; 
	float b = -2; 
	float c = - 4; 
	distance(x, y, a, b, c); 
	return 0; 
}

What will be the plain text corresponding to cipher text "YGQ" if hill cipher is used with keyword as "GYBNQKURP"?