WHICH SORTING TECHNIQUE IS BETTER

Insertion Sort:
* Stable
* O(1) extra space
* O(n2) comparisons, O(n) time when nearly sorted

Selection Sort:
    * Not stable
    * O(1) extra space
    * Θ(n2) comparisons
    * Θ(n) swaps

Bubble Sort: 
    * Stable
    * O(1) extra space
    * O(n2) comparisons and swaps,O(n) when nearly sorted

Quick Sort:
    * Not stable
    * O(lg(n)) extra space (see discussion)
    * O(n2) time, but typically O(n·lg(n)) time

Merge Sort:

    # Stable
    # Θ(n) extra space for arrays (as shown)
    # Θ(lg(n)) extra space for linked lists
    # Θ(n·lg(n)) time

VARIABLES & CONSTANTS IN C .....!!

What is a variable?? Why do we use variables??

Variable is data holder, in which we can store some data and we can modify that data later in the program.

In C programming before we store any data in a variable we need to declare that variable.

declaring a variable:
declaring a variable means telling the compiler that what type of values you want store in that variable. 

datatype variablename ; // declaring a variable 

In C we have 4 types of Data Types:
1. int -  for integer values
2. float - for floating points
3. double - for long floating points such as scientific values
4.char  - for characters

declaring variables example: 

int a;  // tells the compiler that a is a integer type variable in which you want to store integer value.

float f; //

double d;

char c; 

once you declare the variables you can store actual values in those variables.

As I told you variable is data holder. so once you declare any variable C compiler will allocate memory depending on the specified data type.

int a; when do you this one C compiler will allocate 4 bytes of space for this variable called a.

its like this  a
                      

C QUESTION AND ANSWERS: 3

1.

Point out the correct statements are correct about the program below? #include int main() { char ch; while(x=0;x<=255;x++) printf("ASCII value of %d character %c\n", x, x); return 0; }

A. The code generates an infinite loop B. The code prints all ASCII values and its characters C. Error: x undeclared identifier D. Error: while statement missing Answer: Option D Explanation: There are 2 errors in this program. 1. "Undefined symbol x" error. Here x is not defined in the program. 2. Here while() statement syntax error. Learn more problems on : Control Instructions Discuss about this problem : Discuss in Forum

2.

What will be the output of the program? #include int main() { int i=-3, j=2, k=0, m; m = ++i && ++j || ++k; printf("%d, %d, %d, %d\n", i, j, k, m); return 0; }

A. 1, 2, 0, 1 B. -3, 2, 0, 1 C. -2, 3, 0, 1 D. 2, 3, 1, 1 Answer: Option C Explanation: Step 1: int i=-3, j=2, k=0, m; here variable i, j, k, m are declared as an integer type and variable i, j, k are initialized to -3, 2, 0 respectively. Step 2: m = ++i && ++j || ++k; becomes m = (-2 && 3) || ++k; becomes m = TRUE || ++k;.  (++k) is not executed because (-2 && 3) alone return TRUE. Hence this statement becomes TRUE. So it returns '1'(one). Hence m=1. Step 3: printf("%d, %d, %d, %d\n", i, j, k, m); In the previous step the value of i,j are increemented by '1'(one). Hence the output is "-2, 3, 0, 1". Learn more problems on : Expressions Discuss about this problem : Discuss in Forum

3.	What will be the output of the program? #include int fun(int, int); typedef int (*pf) (int, int); int proc(pf, int, int); int main() { printf("%d\n", proc(fun, 6, 6)); return 0; } int fun(int a, int b) { return (a==b); } int proc(pf p, int a, int b) { return ((*p)(a, b)); }
	A. 6 B. 1 C. 0 D. -1 Answer: Option B Learn more problems on : Functions Discuss about this problem : Discuss in Forum

4.

What will be the output of the program? #include #define FUN(arg) do\ {\ if(arg)\ printf("IndiaBIX...", "\n");\ }while(--i) int main() { int i=2; FUN(i<3); return 0; }

A. IndiaBIX... IndiaBIX... IndiaBIX B. IndiaBIX... IndiaBIX... C. Error: cannot use control instructions in macro D. No output Answer: Option B Explanation: The macro FUN(arg) prints the statement "IndiaBIX..." untill the while condition is satisfied. Step 1: int i=2; The variable i is declared as an integer type and initialized to 2. Step 2: FUN(i<3); becomes, do { if(2 < 3) printf("IndiaBIX...", "\n"); }while(--2) After the 2 while loops the value of i becomes '0'(zero). Hence the while loop breaks. Hence the output of the program is "IndiaBIX... IndiaBIX..." Learn more problems on : C Preprocessor Discuss about this problem : Discuss in Forum

5.

What will be the output of the program? #include #define MAX(a, b) (a > b ? a : b) int main() { int x; x = MAX(3+2, 2+7); printf("%d\n", x); return 0; }

A. 8 B. 9 C. 6 D. 5 Answer: Option B Explanation: The macro MAX(a, b) (a > b ? a : b) returns the biggest value of the given two numbers. Step 1 : int x; The variable x is declared as an integer type. Step 2 : x = MAX(3+2, 2+7); becomes, => x = (3+2 > 2+7 ? 3+2 : 2+7) => x = (5 > 9 ? 5 : 9) => x = 9 Step 3 : printf("%d\n", x); It prints the value of variable x. Hence the output of the program is 9. Learn more problems on : C Preprocessor Discuss about this problem : Discuss in Forum

6.

What will be the output of the program? #include #define MAX(a, b, c) (a>b ? a>c ? a : c: b>c ? b : c) int main() { int x; x = MAX(3+2, 2+7, 3+7); printf("%d\n", x); return 0; }

A. 5 B. 9 C. 10 D. 3+7 Answer: Option C Explanation: The macro MAX(a, b, c) (a>b ? a>c ? a : c: b>c ? b : c) returns the biggest of given three numbers. Step 1: int x; The variable x is declared as an integer type. Step 2: x = MAX(3+2, 2+7, 3+7); becomes, => x = (3+2 >2+7 ? 3+2 > 3+7 ? 3+2 : 3+7: 2+7 > 3+7 ? 2+7 : 3+7) => x = (5 >9 ? (5 > 10 ? 5 : 10): (9 > 10 ? 9 : 10) ) => x = (5 >9 ? (10): (10) ) => x = 10 Step 3: printf("%d\n", x); It prints the value of 'x'. Hence the output of the program is "10". Learn more problems on : C Preprocessor Discuss about this problem : Discuss in Forum

7.	What will be the output of the program ? #include int main() { int i, a[] = {2, 4, 6, 8, 10}; change(a, 5); for(i=0; i<=4; i++) printf("%d, ", a[i]); return 0; } change(int *b, int n) { int i; for(i=0; i1) = *(b+i)+5; }
	A. 7, 9, 11, 13, 15 B. 2, 15, 6, 8, 10 C. 2 4 6 8 10 D. 3, 1, -1, -3, -5 Answer: Option B Learn more problems on : Pointers Discuss about this problem : Discuss in Forum

8.	In the following program add a statement in the function fact(). such that the factorial gets stored in j. #include void fact(int*); int main() { int i=5, j; fact(&i); printf("%d\n", i); return 0; } void fact(int *j) { static int s=1; if(*j!=0) { s = s**j; *j = *j-1; fact(j); /* Add a statement here */ } }
	A. j=s; B. *j=s; C. *j=&s; D. &j=s; Answer: Option B Learn more problems on : Pointers Discuss about this problem : Discuss in Forum

9.	Is the NULL pointer same as an uninitialised pointer?
	A. Yes B. No Answer: Option B Learn more problems on : Pointers Discuss about this problem : Discuss in Forum

10.

What will be the output of the program if the array begins at address 65486? #include int main() { int arr[] = {12, 14, 15, 23, 45}; printf("%u, %u\n", arr, &arr); return 0; }

A. 65486, 65488 B. 65486, 65486 C. 65486, 65490 D. 65486, 65487 Answer: Option B Explanation: Step 1: int arr[] = {12, 14, 15, 23, 45}; The variable arr is declared as an integer array and initialized. Step 2: printf("%u, %u\n", arr, &arr); Here, The base address of the array is 65486. => arr, &arr is pointing to the base address of the array arr. Hence the output of the program is 65486, 65486 Learn more problems on : Arrays Discuss about this problem : Discuss in Forum

11.

What will be the output of the program ? #include #include int main() { char str1[20] = "Hello", str2[20] = " World"; printf("%s\n", strcpy(str2, strcat(str1, str2))); return 0; }

A. Hello B. World C. Hello World D. WorldHello Answer: Option C Explanation: Step 1: char str1[20] = "Hello", str2[20] = " World"; The variable str1 andstr2 is declared as an array of characters and initialized with value "Hello" and " World" respectively. Step 2: printf("%s\n", strcpy(str2, strcat(str1, str2))); => strcat(str1, str2)) it append the string str2 to str1. The result will be stored instr1. Therefore str1 contains "Hello World". => strcpy(str2, "Hello World") it copies the "Hello World" to the variable str2. Hence it prints "Hello World". Learn more problems on : Strings Discuss about this problem : Discuss in Forum

12.	For the following statements will arr[3] and ptr[3] fetch the same character? char arr[] = "IndiaBIX"; char *ptr = "IndiaBIX";
	A. Yes B. No Answer: Option A Explanation: Yes, both the statements prints the same character 'i'. Learn more problems on : Strings Discuss about this problem : Discuss in Forum

13.	It is not possible to create an array of pointer to structures.
	A. True B. False Answer: Option B Learn more problems on : Structures, Unions, Enums Discuss about this problem : Discuss in Forum

14.	Can I increase the size of statically allocated array?
	A. Yes B. No Answer: Option B Learn more problems on : Memory Allocation Discuss about this problem : Discuss in Forum

15.

What will be the output of the program? #include #include void fun1(int num, ....); void fun2(int num, ....); int main() { fun1(1, "Apple", "Boys", "Cats", "Dogs"); fun2(2, 12, 13, 14); return 0; } void fun1(int num, ...) { char *str; va_list ptr; va_start(ptr, num); str = va_arg(ptr, char *); printf("%s", str); } void fun2(int num, ...) { va_list ptr; va_start(ptr, num); num = va_arg(ptr, int); printf("%d", num); }

A. Dogs 12 B. Cats 14 C. Boys 13 D. Apple 12 Answer: Option D Learn more problems on : Variable Number of Arguments Discuss about this problem : Discuss in Forum

16.	Point out the error in the following program. #include #include void display(char *s, ...); void show(char *t, ...); int main() { display("Hello", 4, 12, 13, 14, 44); return 0; } void display(char *s, ...) { show(s, ...); } void show(char *t, ...) { int a; va_list ptr; va_start(ptr, s); a = va_arg(ptr, int); printf("%f", a); }
	A. Error: invalid function display() call B. Error: invalid function show() call C. No error D. Error: Rvalue required for t Answer: Option B Explanation: The call to show() is improper. This is not the way to pass variable argument list to a function. Learn more problems on : Variable Number of Arguments Discuss about this problem : Discuss in Forum

17.	In a function that receives variable number of arguments the fixed arguments passed to the function can be at the end of argument list.
	A. True B. False Answer: Option B Learn more problems on : Variable Number of Arguments Discuss about this problem : Discuss in Forum

18.	What will be the output of the program? #include int main() { char huge *near *far *ptr1; char near *far *huge *ptr2; char far *huge *near *ptr3; printf("%d, %d, %d\n", sizeof(ptr1), sizeof(*ptr2), sizeof(**ptr3)); return 0; }
	A. 4, 4, 4 B. 2, 4, 4 C. 4, 4, 2 D. 2, 4, 8 Answer: Option A Learn more problems on : Complicated Declarations Discuss about this problem : Discuss in Forum

19.	What will be the output of the program? #include int main() { char huge *near *ptr1; char huge *far *ptr2; char huge *huge *ptr3; printf("%d, %d, %d\n", sizeof(ptr1), sizeof(ptr2), sizeof(ptr3)); return 0; }
	A. 4, 4, 8 B. 2, 4, 4 C. 4, 4, 2 D. 2, 4, 8 Answer: Option B Learn more problems on : Complicated Declarations Discuss about this problem : Discuss in Forum

20.

ftell() returns the current position of the pointer in a file stream.

A. True B. False Answer: Option A Explanation: The ftell() function shall obtain the current value of the file-position indicator for the stream pointed to by stream. Example: #include int main(void) { FILE *stream; stream = fopen("MYFILE.TXT", "w+"); fprintf(stream, "This is a test"); printf("The file pointer is at byte %ld\n", ftell(stream)); fclose(stream); return 0; } Learn more problems on : Library Functions Discuss about this problem : Discuss in Forum Speak Now