CS 261 Data Structures questions(solved & verified for accuracy)

CS 261 Data Structures
questions(solved & verified for
accuracy)
What will be the output?


int arr[] = {1,2,3,4,5);
int *ptr = arr;
*ptr = 10;
printf("Output 1: %d \n", arr[0]);
printf("Output 2: %d \n", *(ptr+2)); - answer Output 1: 10
Output 2: 3


Output?


int total = 0;
For(int i = 1; i <= 6; i++){
if(i%2 == 0){
total += i;
printf("total = %d \n", total);
}
} - answer total = 2
total = 4
total = 6
total = 12

, What is a dynamic array in C? - answer An array whose size can be
changed at runtime


Value of ptr after memory allocation?


int *ptr;
ptr = (int*)malloc(sizeof(int) *5); - answer Address of first element.


sizeof(int) makes 4 bytes, times 5 equals 20 bytes. int* before
malloc specifies the pointer returned by malloc will point to an
integer.


Which header file do you include to use to include the malloc
function in C? - answer <stdlib.h>


How would you write a struct with two member int and char? -
answer struct MyStruct{ int a; char b;};


What is printed?


int a=10, b=20, c=30;
int *array[3] = {&a, &b, &c};
printf("%d", *array[2]); - answer 30


Output?


int *arr = (int*)malloc(6*sizeof(int));
for(int i =0; i < 6;i++){
arr[i] = i * 2;
}