# Recent questions and answers in Programming and DS

1
Suppose you are given an implementation of a queue of integers. The operations that can be performed on the queue are: $isEmpty (Q)$ - returns true if the queue is empty, false otherwise. $delete (Q)$ - deletes the element at the front of the queue and returns its value ... at the front of the queue $Q$ and inserts it at the rear keeping the other elements in the same order Empties the queue $Q$
2
Consider the following function definition. void greet(int n) { if(n>0) { printf("hello"); greet(n-1); } printf("world"); } If you run greet(n) for some non-negative integer n, what would it print? n times "hello", followed by n+1 times "world" n times "hello", followed by n times "world" n times "helloworld" n+1 times "helloworld" n times "helloworld", followed by "world"
3
Consider the following statements. $S_1$: The sequence of procedure calls corresponds to a preorder traversal of the activation tree. $S_2$: The sequence of procedure returns corresponds to a postorder traversal of the activation tree. Which one of the following options is correct? $S_1$ is true and ... $S_2$ is true $S_1$ is true and $S_2$ is true $S_1$ is false and $S_2$ is false
4
Consider the following operation along with Enqueue and Dequeue operations on queues, where $k$ is a global parameter. MultiDequeue(Q){ m = k while (Q is not empty) and (m > 0) { Dequeue(Q) m = m – 1 } } What is the worst case time complexity of a sequence of $n$ queue operations on an initially empty queue? $Θ(n)$ $Θ(n + k)$ $Θ(nk)$ $Θ(n^2)$
5
Consider the process of inserting an element into a $Max \: Heap$, where the $Max \: Heap$ is represented by an $array$. Suppose we perform a binary search on the path from the new leaf to the root to find the position for the newly inserted element, the number of $comparisons$ performed is: $\Theta(\log_2n)$ $\Theta(\log_2\log_2n)$ $\Theta(n)$ $\Theta(n\log_2n)$
1 vote
6
Consider the following $\text{ANSI C}$ program. #include <stdio.h> int main() { int arr[4][5]; int i, j; for (i=0; i<4; i++) ​​​​​​{ for (j=0; j<5; j++) { arr[i][j] = 10 * i + j; } } printf(“%d”, *(arr[1]+9)); return 0; } What is the output of the above program? $14$ $20$ $24$ $30$
7
First, consider the tree on the left. On the right, the nine nodes of the tree have been assigned numbers from the set $\left\{1, 2,\ldots,9\right\}$ so that for every node, the numbers in its left subtree and right subtree lie in disjoint intervals (that is, all numbers in one subtree are less than all numbers in ... $2^{4}.3^{2}.5.9=6480$ $2^{3}.3.5.9=1080$ $2^{4}=16$ $2^{3}.3^{3}=216$
1 vote
8
void main(){ static int i=5; printf("%d",i--); If(i) main() } What will be output of the program}
9
What is the output of the following C program? #include<stdio.h> void main(void){ int shifty; shifty=0570; shifty=shifty>>4; shifty=shifty<<6; printf("The value of shifty is %o \n",shifty); } The value of shifty is 15c0 The value of shifty is 4300 The value of shifty is 5700 The value of shifty is 2700
1 vote
10
Consider the following $\text{ANSI C}$ function: int SimpleFunction(int Y[], int n, int x) { int total = Y[0], loopIndex; for (loopIndex=1; loopIndex<=n-1; loopIndex++) total=x*total +Y[loopIndex]; return total; } Let $\textsf{Z}$ be an array of $10$ elements with $\textsf{Z}[i]=1$, for all $i$ such that $0 \leq i \leq 9$. The value returned by $\textsf{SimpleFunction(Z},10,2)$ is __________
11
Consider the following snippet of a C program. Assume that swap $(\&x, \&y)$ exchanges the content of $x$ and $y$: int main () { int array[] = {3, 5, 1, 4, 6, 2}; int done =0; int i; while (done==0) { done =1; for (i=0; i<=4; i++) { if (array[i] < array[i+1] ... if (array[i] > array[i-1]) { swap(&array[i], &array[i-1]); done =0; } } } printf( %d , array[3]); } The output of the program is _______
12
Consider the following $\text{ANSI C}$ program #include <stdio.h> int foo(int x, int y, int q) { if ((x<=0) && (y<=0)) return q; if (x<=0) return foo(x, y-q, q); if (y<=0) return foo(x-q, y, q); return foo(x, y-q, q) + foo(x-q, y, q); } int main( ) { int r = foo(15, 15, 10); printf(“%d”, r); return 0; } The output of the program upon execution is _________
13
Consider the following program: int f (int * p, int n) { if (n <= 1) return 0; else return max (f (p+1, n-1), p[0] - p[1]); } int main () { int a[] = {3, 5, 2, 6, 4}; print f(" %d", f(a, 5)); } Note: $max (x, y)$ returns the maximum of $x$ and $y$. The value printed by this program is ________.
14
Consider the following recursive definition of $fib$: fib(n) := if n = 0 then 1 else if n = 1 then 1 else fib(n-1) + fib(n-2) The number of times $fib$ is called (including the first call) for evaluation of $fib(7)$ is___________.
15
Consider the following $\text{ANSI C}$ function: int SomeFunction (int x, int y) { if ((x==1) || (y==1)) return 1; if (x==y) return x; if (x > y) return SomeFunction(x-y, y); if (y > x) return SomeFunction (x, y-x); } The value returned by $\textrm{SomeFunction(15, 255)}$ is __________
16
Let $P$ be an array containing $n$ integers. Let $t$ be the lowest upper bound on the number of comparisons of the array elements, required to find the minimum and maximum values in an arbitrary array of $n$ elements. Which one of the following choices is correct? $t>2n-2$ ... $t>n \text{ and } t\leq 3\lceil \frac{n}{2}\rceil$ $t>\lceil \log_2(n)\rceil \text{ and } t\leq n$
17
Consider the following sequence of operations on an empty stack. $\textsf{push}(54);\textsf{push}(52);\textsf{pop}();\textsf{push}(55);\textsf{push}(62);\textsf{s}=\textsf{pop}();$ ... $\textsf{s+q}$ is ___________.
18
A binary search tree $T$ contains $n$ distinct elements. What is the time complexity of picking an element in $T$ that is smaller than the maximum element in $T$? $\Theta(n\log n)$ $\Theta(n)$ $\Theta(\log n)$ $\Theta (1)$
1 vote
19
​​​​​Let $H$ be a binary min-heap consisting of $n$ elements implemented as an array. What is the worst case time complexity of an optimal algorithm to find the maximum element in $H$? $\Theta (1)$ $\Theta (\log n)$ $\Theta (n)$ $\Theta (n \log n)$
20
In the code fragment given below, $\mathsf{start}$ and $\mathsf{end}$ are integer values and $\mathsf{prime(x)}$ is a function that returns $\mathsf{true}$ if $\mathsf{x}$ is a prime number and $\mathsf{false}$ otherwise. i:=0; j:=0; k:=0; from (m := start; m <= end; m := m+1){ if ( ... } } At the end of the loop: $k == i-j.$ $k == j-i.$ $k == -j-i.$ Depends on $\mathsf{start}$ and $\mathsf{end}$
1 vote
21
State True/False: "If two operators in an expression have equal precedence but different associativity then order of their evaluation is compiler dependent." Considering my adaptation to this question: if * and ^(exponentiation) has same precedence if * associate from right to left and ^ associates from left to right, then what will be the result of 2*2^3*4 ?
22
Hi, Is there any smart way to learn operator precedence table ? (means can we form some kind of logical connection instead of mugging entire table.) If some good reference could be provided then it will be great help. PS: http://www.geeksforgeeks.org/c-operator-precedence-associativity/
23
An $articulation$ $point$ in a connected graph is a vertex such that removing the vertex and its incident edges disconnects the graph into two or more connected components. Let $T$ be a $\text{DFS}$ tree obtained by doing $\text{DFS}$ in a connected undirected graph $G$. Which of the following ... and $y$ is a descendent of $u$ in $T$, then all paths from $x$ to $y$ in $G$ must pass through $u$.
24
Consider a complete binary tree with $7$ nodes. Let $A$ denote the set of first $3$ elements obtained by performing Breadth-First Search $\text{(BFS)}$ starting from the root. Let $B$ denote the set of first $3$ elements obtained by performing Depth-First Search $\text{(DFS)}$ starting from the root. The value of $\mid A-B \mid$ is _____________
1 vote
25
Consider the following$\text{ ANSI C}$ program. #include <stdio.h> int main() { int i, j, count; count=0; i=0; for (j=-3; j<=3; j++) { if (( j >= 0) && (i++)) count = count + j; } count = count + ... will compile successfully and output $10$ when executed The program will compile successfully and output $8$ when executed The program will compile successfully and output $13$ when executed
26
Consider the following $\text{ANSI C}$ program: #include <stdio.h> #include <stdlib.h> struct Node{ int value; struct Node *next;}; int main( ) { struct Node *boxE, *head, *boxN; int index=0; boxE=head= (struct Node *) malloc(sizeof(struct Node)) ... $\textsf{return}$ which will be reported as an error by the compiler It dereferences an uninitialized pointer that may result in a run-time error
27
What item is at the root after the following sequence of insertions into an empty splay tree : $1, 11, 3, 10, 8, 4, 6, 5, 7, 9, 2, ?$ $1$ $2$ $4$ $8$
28
In C programming language, if the first and the second operands of operator $+$ are of types int and float, respectively, the result will be of type int float char long int
29
Consider the following statements #define hypotenuse (a, b) sqrt (a*a+b*b); The macro call hypotenuse(a+2,b+3); Finds the hypotenuse of a triangle with sides $a+2$ and $b+3$ Finds the square root of $(a+2)^2$ and $(b+3)^2$ Is invalid Find the square root of $3 *a+4*b+5$
30
In BFS of a directed graph, we don't have forward edges.Only tree edge,cross edge or back edge. Below is a sample graph I have taken and classified edge types. Please verify guys whether it's correct. The algorithm I have used is the ... by "redtuna" in the selected answer here. https://stackoverflow.com/questions/29631211/edge-classification-during-breadth-first-search-on-a-directed-graph
31
How to approach this problem ? what does "right rotation at K" mean ? is it LR
1 vote
32
Consider the following pseudo-code fragment, where $a$ and $b$ are integer variables that have been initialized: /* Pre-conditions : $(a > 1 \wedge a < b)$ */ /* Assume that overflow never occurs */ int $x=0$; int $p=1$; while $(p<b) \{$ $p=p*a$; $x=x+1$; $\}$ ... $\lfloor \: \: \rfloor$ means floor */ $\lfloor \log_a^b \rfloor$ /* $\lceil \: \: \rceil$ means ceil */
33
Suppose you are compiling on a machine with $1$-byte chars, $2$-byte shorts, $4$-byte ints, and $8$-byte doubles, and with alignment rules that require the address of every primitive data element to be an integer multiple of the element's size. Suppose further that the compiler is not ... ; double r; int i; } A[10]; /*10 element array of structs */ $150$ bytes $320$ bytes $240$ bytes $200$ bytes
34
A complete $n$-ary tree is a tree in which each node has $n$ children or no children. Let $I$ be the number of internal nodes and $L$ be the number of leaves in a complete $n$-ary tree. If $L=41$, and $I=10$, what is the value of $n$? $3$ $4$ $5$ $6$
35
In a binary max heap containing $n$ numbers, the smallest element can be found in ______ $O(n)$ $O(\log _2 n)$ $O(1)$ $O(\log_2 \log_2 n)$
36
Which of the following statements are true? Minimax search is breadth-first; it processes all the nodes at a level before moving to a node in next level. The effectiveness of the alpha-beta pruning is highly dependent on the order in which the states are examined The alpha-beta search algorithms computes the same ... and $(c)$ only $(a)$ and $(d)$ only $(b)$ and $(c)$ only $(c)$ and $(d)$ only
37
Match $\text{List I}$ with $\text{List II}$ Let $R_1=\{(1,1), (2,2), (3,3)\}$ and $R_2=\{(1,1), (1,2), (1,3), (1,4)\}$ ... answer from the options given below: $A-I, B-II, C-IV, D-III$ $A-I, B-IV, C-III, D-II$ $A-I, B-III, C-II, D-IV$ $A-I, B-IV, C-II, D-III$
An external variable is globally accessible by all functions has a declaration “extern” associated with it when declared within a function will be initialized to $0$ if not initialized all of these
A hash table with $10$ buckets with one slot per bucket is depicted. The symbols, $S1$ to $S7$ are initially emerged using a hashing function with linear probing. Maximum number of comparisons needed in searching an item that is not present is $6$ $5$ $4$ $3$
A full binary tree with $n$ non-leaf nodes contains $\log_ 2 n$ nodes $n+1$ nodes $2n$ nodes $2n+1$ nodes