Amazon 1st round questions

here is the
Amazon 1st round questions...

Part A
-------

1.int foo(int n)
{
if(n<=0) return -1;
else
print n;
n=n/2;
return foo(n);
}

find the complexity ? Ans: O(log n)

2.What is the Big 'O' notation for (n+10)*(n-6) ?

Ans : O(n^2)

3.which is better function A or c? under what circumstances?

void A()
{
while(testandset(lock));
}

void c()
{
while(testandset(lock))
{
try{
sleep(x);
}
catch(Exception e){ }
}
}

testandset function is....

boolean testandset(lock)
{
if(lock) return false;
lock = Locketd;
return true;
}

4. Execution time of the tasks are 4,4,7,8,9 . by what way these task should execute so that average time shoubld be least and write the schedule.

5. write the query to find second highest mark.
Student(rollnumber int , name varchar,marks int)

6. find the minimum of x,y without using branching statements?
a)(y-x)-(x-y)<<1
b) x>y?x:y
c) y+((x-y)&-(x d)x^((x^y)&-(x
7.write the grammar for the expression 1+2*3(4+5)*(6*7)

8.another TOC question to find what the given transition diagram does?

9.given a java program(binary search program) , debug the program.

10. given a number, find whether it is a power of 2?

a)num & (num-1)
b)num && (num & (num-1))
c)num && (num & num-1)
d)num && (num-1)

11. given a code:
int hashcode()
{
return 0;
}
find complexity ?
12. x % y ---> leaves remainder 24
2x % y ---> leaves remainder 11
what is the value of y?


Part B
------

1. given an array {5,3,6,2,7,1,4}. sort the odd position elements into descending order and even position elements into ascending order.

O/P : { 7,6,5,4,1,2,3}

2. given two numbers.
reverse 2 numbers.
add those two reversed numbers.

Input : 31000
2500

Output : 65

In placements, every company 's first round ll be very basic. clearing the first round is the big hurdle. it contains the questions of all field.