Tech Mahindra C/C++/ Java Interview Questions , C,C++,Java Interview questions

Tech Mahindra C/C++/ Java Interview Questions



1. #include
* What is wrong in the following problem
main() {
int i,j;
j = 10;
i = j++ - j++;
printf("%d %d", i,j);
}
ans: 0, 12
2.#include
* What is the output of the following problem
main() {
int j;
for(j=0;j<3;j++)
foo();
}
foo() {
static int i = 10;
i+=10;
printf("%d\n",i);
}
/* Out put is (***since static int is used i value is retained between
* 20 function calls )
* 30
* 40
*
/
3.#include
#include
#include
/* This is asked in PCS Bombay walk-in-interview
* What is wrong in the following code
*/
main()
{
char *c;
c = "Hello";
printf("%s\n", c);
}
/*ans:- Hello, The code is successfully running */
4. #include
/* This problem is given in PCS BOMBAY walk-in-interview.
* What is the final value of i and how many times loop is
* Executed ?
*/
main()
{
int i,j,k,l,lc=0;
/* the input is given as 1234 567 */
printf("Enter the number string:<1234 567 \n");
scanf("%2d%d%1d",&i,&j,&k);
for(;k;k--,i++)
for(l=0;l
printf("%d %d\n",i,l);}
printf("LOOPS= %d\n", lc-1);
}
/* Ans: i = 16, and loop is executed for 169 times */
5.#include
/* This is given in PCS Bombay walk-in-interview */
/* What is the output of the following program */
main() {
union {
int a;
int b;
int c;
} u,v;
u.a = 10;
u.b = 20;
printf("%d %d \n",u.a,u.b);
}
/* Ans : The latest value assigned to any of the union member
will be present in the union members so answer is
20 20
*/
6.#include
main()
{
float i, j;
scanf("%f %f", &i, &j);
printf("%.2f %.3f", i, j);
}
/Ans:- 123.34 3. 234 */
7.#include
/* This is given in PCS Bombay walk-in-interview
* What is the out put of the following problem ?
*/
main()
{
char *str = "12345";
printf("%c %c %c\n", *str, *(str++), *(str++));
}
/* Ans: It is not 1 2 3
* But it is 3 2 1 Why ??
*/
8.#include
/* This problem is asked in PCS Bombay Walk-in-interview
* Write a macro statement to find maximum of a,b
*/
#define max(a,b) (ab)?a:b
main()
{
int a,b;
a=3;
b=4;
printf("%d",max(a,b));
}
/* Ans is very simple the coding is just for testing it
and output is 4 */
~
9.#include
/* This problem is asked in PCS Bombay
* What is the output of the following coding
*/
main()
{
int len=4;
char *st="12345678";
st = st -len;
printf("%c\n",*st);
}
/* Ans : It will print some junk value */
~
10.#include
main()
{
func(1);
}
func(int i){
static char *str ={ "One","Two","Three","Four"};
printf("%s\n",str[i++]);
return;
}
/* Ans:- it will give warning because str is pointer to the char but
it is initialized with more values
if it is not considered then the answer is Two */
11.
#include
main()
{
int i;
for (i=1;i<100; i++)
printf("%d %0x\n",i,i);
}
/* Ans:- i is from 1 to 99 for the first format,
for the second format 1to9, ato f, 10 to 19,1ato1f, 20 to 29, etc */

12.#include
/* This problem is asked in PCS Bombay walk-in-interview
* In the following code please write the syntax for
* assing a value of 10 to field x of s and id_no 101 of s
*/
struct {
int x;
int y;
union {
int id_no;
char *name;
}b;
}s,*st;
main()
{
st = &s;
st-x=10;
st-b.id_no = 101;
printf("%d %d\n",s..x,s.b.id_no);
}
/* Ans: The answer is st-x=10;
* st-b.id_no=101;
*/
13.#include
/* This problem was asked in PCS Bombay in a walk-in-interview
* Write a recursive function that calculates
* n * (n-1) * (n-2) * ....... 2 * 1
*/
main() {
int factorial(int n);
int i,ans;
printf("\n Enter a Number:");
scanf("%d",&i);
ans = factorial(i);
printf("\nFactorial by recursion = %d\n", ans);
}
int factorial(int n)
{
if (n <= 1) return (1);
else
return ( n * factorial(n-1));
}
~
14.#include
/* This problem is asked in PCS Bombay walk-in-interview
* What is the output of the following problem
*/
main(){
int j,ans;
j = 4;
ans = count(4);
printf("%d\n",ans);
}
int count(int i)
{
if ( i < 0) return(i);
else
return( count(i-2) + count(i-1));
}
/* It is showing -18 as an answer */
15.#include
main()
{
int i=4;
if(i=0)
printf("statement 1");
else
printf("statement 2");
}
/* statement 2 */

This is pcsb paper.
1. #include
* What is wrong in the following problem
main() {
int i,j;
j = 10;
i = j++ - j++;
printf("%d %d", i,j);
}
ans: 0, 12
2.#include
* What is the output of the following problem
main() {
int j;
for(j=0;j<3;j++)
foo();
}
foo() {
static int i = 10;
i+=10;
printf("%d\n",i);
}
/* Out put is (***since static int is used i value is retained between
* 20 function calls )
* 30
* 40
*
/
3.#include
#include
#include
/* This is asked in PCS Bombay walk-in-interview
* What is wrong in the following code
*/
main()
{
char *c;
c = "Hello";
printf("%s\n", c);
}
/*ans:- Hello, The code is successfully running */
4. #include
/* This problem is given in PCS BOMBAY walk-in-interview.
* What is the final value of i and how many times loop is
* Executed ?
*/
main()
{
int i,j,k,l,lc=0;
/* the input is given as 1234 567 */
printf("Enter the number string:<1234 567 \n");
scanf("%2d%d%1d",&i,&j,&k);
for(;k;k--,i++)
for(l=0;l
printf("%d %d\n",i,l);}
printf("LOOPS= %d\n", lc-1);
}
/* Ans: i = 16, and loop is executed for 169 times */
5.#include
/* This is given in PCS Bombay walk-in-interview */
/* What is the output of the following program */
main() {
union {
int a;
int b;
int c;
} u,v;
u.a = 10;
u.b = 20;
printf("%d %d \n",u.a,u.b);
}
/* Ans : The latest value assigned to any of the union member
will be present in the union members so answer is
20 20
*/
6.#include
main()
{
float i, j;
scanf("%f %f", &i, &j);
printf("%.2f %.3f", i, j);
}
/Ans:- 123.34 3. 234 */
7.#include
/* This is given in PCS Bombay walk-in-interview
* What is the out put of the following problem ?
*/
main()
{
char *str = "12345";
printf("%c %c %c\n", *str, *(str++), *(str++));
}
/* Ans: It is not 1 2 3
* But it is 3 2 1 Why ??
*/
8.#include
/* This problem is asked in PCS Bombay Walk-in-interview
* Write a macro statement to find maximum of a,b
*/
#define max(a,b) (ab)?a:b
main()
{
int a,b;
a=3;
b=4;
printf("%d",max(a,b));
}
/* Ans is very simple the coding is just for testing it
and output is 4 */
~
9.#include
/* This problem is asked in PCS Bombay
* What is the output of the following coding
*/
main()
{
int len=4;
char *st="12345678";
for(i=0; i<6; i++)
st = st -len;
printf("%c\n",*st);
}
/* Ans : It will print some junk value */
~
10.#include
main()
{
func(1);
}
func(int i){
static char *str ={ "One","Two","Three","Four"};
printf("%s\n",str[i++]);
return;
}
/* Ans:- it will give warning because str is pointer to the char but
it is initialized with more values
if it is not considered then the answer is Two */
11.
#include
main()
{
int i;
for (i=1;i<100; i++)
printf("%d %0x\n",i,i);
}
/* Ans:- i is from 1 to 99 for the first format,
for the second format 1to9, ato f, 10 to 19,1ato1f, 20 to 29, etc */

12.#include
/* This problem is asked in PCS Bombay walk-in-interview
* In the following code please write the syntax for
* assing a value of 10 to field x of s and id_no 101 of s
*/
struct {
int x;
int y;
union {
int id_no;
char *name;
}b;
}s,*st;
main()
{
st = &s;
st-x=10;
st-b.id_no = 101;
printf("%d %d\n",s.x,s.b.id_no);
}
/* Ans: The answer is st-x=10;
* st-b.id_no=101;
*/
13.#include
/* This problem was asked in PCS Bombay in a walk-in-interview
* Write a recursive function that calculates
* n * (n-1) * (n-2) * ....... 2 * 1
*/
main() {
int factorial(int n);
int i,ans;
printf("\n Enter a Number:");
scanf("%d",&i);
ans = factorial(i);
printf("\nFactorial by recursion = %d\n", ans);
}
int factorial(int n)
{
if (n <= 1) return (1);
else
return ( n * factorial(n-1));
}
~
14.#include
/* This problem is asked in PCS Bombay walk-in-interview
* What is the output of the following problem
*/
main(){
int j,ans;
j = 4;
ans = count(4);
printf("%d\n",ans);
}
int count(int i)
{
if ( i < 0) return(i);
else
return( count(i-2) + count(i-1));
}
/* It is showing -18 as an answer */
15.#include
main()
{
int i=4;
if(i=0)
printf("statement 1");
else
printf("statement 2");
}
/* statement 2 */


1. What is the output of the following program?
class complex{
double re;
double im;
public:
complex() : re(0),im(0) {}
complex(double n) { re=n,im=n;};
complex(int m,int n) { re=m,im=n;}
void print() { cout«re; cout«im;}
};

void main(){
complex c3;
double i=5;
c3 = i;
c3.print();
}

a) 4,5 b) 3,5 c) 5,5 d) None of the above

2. What is the error in the class declaration?
class something
{
char *str;
public:
something(){
st = new char[10]; }
~something()
{
delete str;
}
};

a) pointer not defined
b) st not defined
c) deleting a pointer is wrong
d) None of the above

3. Find the error in the class declaration?
class temp
{
int value1;
mutable int value2;
public :
void fun(int val)
const{
((temp*) this)->value1 = 10;
value2 = 10;
}
};

a) mutable is wrongly used
b) const is not a function
c) wrong use of pointer
d) None of the above

4. What is spanning tree?
5. Explain traveling salesman problem?
6. What is the difference between BFS and DFS?
7. Write down the prim’s algorithm?
8. What is JVM? What is its use?
9. How to do memory management in JAVA?
10. Why are constructors and destructors used?

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