Reverse a Linearly Linked List
Given a linear linked list, write a function that will reverse the linked list in O(n) time using a constant amount of extra memory.
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Implment A Stack Using A Linked List
Given a linear linked list, write a function that will reverse the linked list in O(n) time using a constant amount of extra memory.
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There are three variants of this question, but the basic idea is essentially the same. A palindrome is a string of values such that the first value is the same as the last value, the second value is the same as the second to last value, etc. Thus, 101, 111, 11, AAAA, and 1122330332211 are palindromes.
int DetectPal( char pch[], int Len );
typedef struct
{
Elt * next;
int value; /* or character, or short, etc, etc*/
} Elt;
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Determine the Binary Representation of a given number
Given a long integer, write a function which will display
which bits are 1. In other words, if you call the function with
the argument 4, it should say something like:
(MSB)
00000000 00000000 00000000 00000100
(LSB)
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Write BASIC's Left and Right functions
char *Left( char *sz, int n); // returns the first n
characters of the string sz
char *Right(char *sz, int n); // returns the last n characters of
the string sz
//more precisely, it will return a string that starts at the nth
character of sz
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Swap values w/o using more memory
Write code in C to swap the values of two integers i and j without allocating any additional memory. What happens if i & j are the same variable (e.g., they're both variables passed by reference?)
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Eliminate duplicate values in an array
Given an array of n sorted elements, write a function Compact that will remove all duplicate elements. Compact should be able to compact the array in-place, or copy the (non duplicate) values to somewhere else. You may assume that the array is of integers.
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Consider the base -2 number system. That is, the places are
worth:
-2^0 = 1
-2^1 = -2
-2^2 = 4
-2^3 = -8
-2^4 = 16
Etc.
Figure out an algorithm for adding two such numbers. Converting
to binary? Converting from binary? Finding the complement?
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Write an efficient algorithm for finding x ^y (x raised to the
power of y), where x is an int and y is a positive integer.
int PowerOf( int x, unsigned int y)
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Write pair of functions that deal cards
Write a pair of functions to deal cards. One functions initializes the deck, the other function returns a card. A card is a number that ranges from 0 to 51. The algorithm should be efficient.
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unsigned int foo( unsigned int i)
{
unsigned int j = 0;
while( i )
{
++j;
i &= i - 1;
}
return j;
}
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What is the output of these lines of C code:
for (i = 0; i <2; i++) for (j="2;" j> 0; j--) {
if (i == j)
continue;
printf("Out");
}
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You own a gold mine, and you have only one worker. This worker is paid 1 ounce of gold per day. Being a hard worker, the worker works seven days a week. To pay this worker, you have a single, seven ounce bar of gold. How can the bar be cut ONLY twice so that the worker gets exactly his total pay on each day? (I.E., at the end of the first day, the worker possesses one ounce of gold. At the end of the second day, the worker possesses a total of two ounces of gold, three ounces are possessed at the end of the third day, etc)
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Given: There exist two rooms, and in one room there are three light switches, all start in the " down " position. In the other room, there exist three light bulbs, all of which start in the " off " state. You are allowed to enter each room once AND only once in any order you please, but once you've left the room, you may never reenter or perceive the contents. You cannot perceive the contents of either room from outside the room. How can you determine which light switch controls which incandescent light bulb?
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Given: A red colored basket containing an effectively infinite
number of red colored (and ONLY red colored) golf balls and a
green colored basket containing an effectively infinite number of
green colored (and ONLY green colored) golf balls. A
>B>Cycle consists of taking G (some arbitrary number) of
golf balls out of one basket and dropping them into the basket of the
other color, and then taking G (same number as before) randomly selected
golf balls out of the second basket, and dumping that handful
into the first basket. It doesn't matter which color basket you
start with, and you can pick up golf balls that you just dropped
into a basket (so you could pick 5 red golf balls out of the red
basket, dump them into the green basket, and then pick 5 red golf
balls out of the green basket and put them into the red>
Prove that the following statement is true: After an arbitrary
number of cycles, the number of red golf balls in the green
basket is equal to the number of green golf balls in the red
basket.
There is a similar question about two colors of paint, except
that the question is phrased "You have two colors of paint.
You take some paint out of one can and dump it into the other
can. You take an identical volume of paint of that can and dump
it back into the first can. After doing this for (N) steps, how
much oppositely colored paint does each can contain?"
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How to get four gallons using 5 and 3 gallon bottles
For anyone whoÕs ever seen Die Hard 3: Die Hard with a Vengeance (A.k.a., Die Hard 3: Die Hardest), this should be familiar. The situation is this: You are standing in a pool with a five gallon bottle and a three gallon bottle, and you have to figure out how to get PRECISELY four gallons into the five gallon bottle. ThereÕs an effectively unlimited supply of water that youÕre standing in, but you canÕt use any other containers, measuring devices, or modify either of the bottles (such as by marking them)
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A cup of blue pigment and a cup of red pigment are taken from their respective cans and dumped into the same empty can. The pigments are then mixed vigorously. One cup of pigment from the mixed can is then taken and dumped into the blue can. The remainder of the mixed can is the poured into the red can. How much red is in the blue can, and how much blue is in the red can?
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How many starting points are there on the Earth such that if a person traveled one mile south, one mile east and on mile north (s)he would end up in the placed that (s)he started at?
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Given ten masses and a scale...
Given ten masses, nine of which are equivalent, and one balance, how can you use the balance no more than four times and discover which masses is not the equivalent one?(Note: The solution should work if the unique mass is less than or greater than the nine equal masses)
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Given: 10 "Big" Boxes, each of a unique color (for
identification), each containing 10 "Small" boxes (of
the same color as the big box they're in). Each of the small
boxes contains 10 ball bearings in 9 of the ten big boxes. One of
the big boxes had a problem during manufacturing and each of it's small
boxes now only contains nine Ball Bearings each (one short). You
can open the big boxes and remove the small boxes, but you cannot
open the small boxes. The scale has only one platform (it's not a
balancing scale, but a bathroom-type scale), and will read in
units equal to 1 Ball Bearings weight (the boxes themselves are
of negligible weight). For example, if you put a small box
containing 10 Ball Bearings, it would read 10.
If you can use the scale once, how can you find out which big box
is incorrect (contains only 9 Ball Bearings per Small box)?
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You are given a glass of pure water with an ice cube in the glass. The water in the glass comes up to the rim of the glass exactly.When the ice cube melts, will the water overflow?
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Sum the integers from 1 to 100 in your head
Quickly sum up all the integers between 1 and 100 (inclusive at both ends) quickly, in your head
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You have an infinite x,y plane. Each point is colored arbitrarily either red or black. Proove that given any distance, you can find two points on the plane that are the same color & that are that distance apart. (NB: A formal proof is not needed. )
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Joe and Fred are standing in a underground tunnel for trains, and they are W meters away from the nearest end. A train enters the tunnel's nearest end traveling at X meters per second. At the instant that the train enters the tunnel, both Joe and Fred begin running for an exit: Joe for the far exit, and Fred from the near end (ie, towards the oncoming train). If Joe and Fred both move at Y meters per second, how far will Joe have gone when Fred gets hit by the oncoming train?
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