GATE CS Programming and Data Structures questions

Consider the following C program: #include <stdio.h> int main() { int arr[]={1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 5}, *ip=arr+4; printf(“%d\n”, ip[1]); return 0; } The number that will be displayed on execution of the program is _______

Consider the following C program: #include <stdio.h> int r() { static int num=7; return num--; } int main() { for (r();r();r()) printf(“%d”,r()); return 0; } Which one of the following values will be displayed on execution of the programs?

Consider the following statements: The smallest element in a max-heap is always at a leaf node The second largest element in a max-heap is always a child of a root node A max-heap can be constructed from a binary search tree in $\Theta(n)$ time A binary search tree can be constructed from a max-heap in $\Theta(n)$ time Which of the above statements are …

Let $T$ be a full binary tree with $8$ leaves. (A full binary tree has every level full.) Suppose two leaves $a$ and $b$ of $T$ are chosen uniformly and independently at random. The expected value of the distance between $a$ and $b$ in $T$ (ie., the number of edges in the unique path between $a$ and $b$) is (rounded off to $2$ decimal …

Consider the following C program: #include <stdio.h> int main() { float sum = 0.0, j=1.0, i=2.0; while (i/j > 0.0625) { j=j+j; sum=sum+i/j; printf("%f\n", sum); } return 0; } The number of times the variable sum will be printed, when the above program is executed, is _________

Consider the following C program: #include <stdio.h> int main() { int a[] = {2, 4, 6, 8, 10}; int i, sum=0, *b=a+4; for (i=0; i<5; i++) sum=sum+(*b-i)-*(b-i); printf("%d\n", sum); return 0; } The output of the above C program is _______

The number of possible min-heaps containing each value from $\{1,2,3,4,5,6,7\}$ exactly once is _______

Consider the following C code. Assume that unsigned long int type length is $64$ bits. unsigned long int fun(unsigned long int n) { unsigned long int i, j=0, sum = 0; for( i=n; i>1; i=i/2) j++; for( ; j>1; j=j/2) sum++; return sum; } The value returned when we call fun with the input $2^{40}$ is:

#include<stdio.h> void fun1(char* s1, char* s2){ char* temp; temp = s1; s1 = s2; s2 = temp; } void fun2(char** s1, char** s2){ char* temp; temp = *s1; *s1 = *s2; *s2 = temp; } int main(){ char *str1="Hi", *str2 = "Bye"; fun1(str1, str2); printf("%s %s", str1, str2); fun2(&str1, &str2); printf("%s %s", str1, str2); return 0; } The output of the …

The postorder traversal of a binary tree is $\text{8, 9, 6, 7, 4, 5, 2, 3, 1}$. The inorder traversal of the same tree is ${8, 6, 9, 4, 7, 2, 5, 1, 3}$. The height of a tree is the length of the longest path from the root to any leaf. The height of the binary tree above is _____

Consider the following $\text{C}$ program: #include<stdio.h> int counter=0; int calc (int a, int b) { int c; counter++; if(b==3) return (a*a*a); else { c = calc(a, b/3); return (c*c*c); } } int main() { calc(4, 81); printf("%d", counter); } The output of this program is ______.

A queue is implemented using a non-circular singly linked list. The queue has a head pointer and a tail pointer, as shown in the figure. Let $n$ denote the number of nodes in the queue. Let 'enqueue' be implemented by inserting a new node at the head, and 'dequeue' be implemented by deletion of a node from the tail. Which one of the following is the time …

Consider the following C program: #include<stdio.h> struct Ournode{ char x, y, z; }; int main() { struct Ournode p={'1', '0', 'a'+2}; struct Ournode *q=&p; printf("%c, %c", *((char*)q+1), *((char*)q+2)); return 0; } The output of this program is:

Consider the C code fragment given below. typedef struct node { int data; node* next; } node; void join(node* m, node* n) { node* p = n; while(p->next != NULL) { p = p->next; } p->next = m; } Assuming that m and n point to valid NULL-terminated linked lists, invocation of join will

The output of executing the following C program is _______________ . #include<stdio.h> int total(int v) { static int count = 0; while(v) { count += v&1; v >>= 1; } return count; } void main() { static int x=0; int i=5; for(; i>0; i--) { x = x + total(i); } printf("%d\n", x); }

Consider the following C program. #include<stdio.h> #include<string.h> void printlength(char *s, char *t) { unsigned int c=0; int len = ((strlen(s) - strlen(t)) > c) ? strlen(s) : strlen(t); printf("%d\n", len); } void main() { char *x = "abc"; char *y = "defgh"; printlength(x,y); } Recall that $strlen$ is defined in $string.h$ as …

Consider the C functions foo and bar given below: int foo(int val) { int x=0; while(val > 0) { x = x + foo(val--); } return val; } int bar(int val) { int x = 0; while(val > 0) { x= x + bar(val-1); } return val; } Invocations of $foo(3)$ and $bar(3)$ will result in:

Consider the following two functions. void fun1(int n) { if(n == 0) return; printf("%d", n); fun2(n - 2); printf("%d", n); } void fun2(int n) { if(n == 0) return; printf("%d", n); fun1(++n); printf("%d", n); } The output printed when $\text{fun1}(5)$ is called is

Let $T$ be a tree with $10$ vertices. The sum of the degrees of all the vertices in $T$ is ________

Consider the following C code: #include<stdio.h> int *assignval (int *x, int val) { *x = val; return x; } void main () { int *x = malloc(sizeof(int)); if (NULL == x) return; x = assignval (x,0); if (x) { x = (int *)malloc(sizeof(int)); if (NULL == x) return; x = assignval (x,10); } printf("%d\n", *x); free(x); } The code suffers from which one of the …