Forum Posts
0 Answers Error in 6th Edition
Maybe you fixed this already in 7th.
- timcrall January 09, 2018
In 6th edition, question 4.11, the question only specifies a binary tree but the answer assumes a binary search tree. Which is exactly a thing you told us to look out for. So I was.
EDIT: Although this doesn't really seem to affect the answer.
Also, for the love of all things holy, invest in some spam-blocking on the forums!| Flag | PURGE 0 Answers String Transformation
You are given 2 Strings A and B. You have to transform A to become B.
- anuj January 07, 2018
Following are the type of transformation possible:
1. pick an alphabet and replace all occurrences of this alphabet in the string by the next alphabet in the sequence[a,b,c,d----y,z]. Note that the next alphabet for z is a. The whole operation counts as one operation with Cost C is given as input.
2.pick an alphabet and replace all occurrences of this alphabet in the string by the previous alphabet in the sequence[a,b,c,d----y,z]. Note that the next alphabet for a is z. The whole operation counts as one operation with Cost D is given as input.
You have to return the minimum cost to transform A to B. if it's not possible return -1
Example:
A: "ab"
B: "cc"
C:2
D:5
Answer : 4
we need two C operations "ab" -->"bb"-->"cc"
Note that the last step of converting all b to c counts as one operation| Flag | PURGE 0 Answers Developing Java game
creating a RESTful service using which players can play a simple game described
- stallapp November 02, 2017
below.
The game should have the following rules:
• The player has an infinite amount of coins.
• The player bets 10 coins to play a normal game round.
• In any round (free or normal), the player has a 30% chance of winning back 20 coins.
• In any round (free or normal), the player also has a 10% chance of triggering a free round where
the player does not have to pay for bet. The free round works in the same way as a normal round except
it costs 0 coins. The free round should follow immediately after the normal round.
• The player can both win coins and free round at the same time.| Flag | PURGE 0 Answers rejected by amazon for no reason
got rejected, I think I did well for all rounds, maybe not behavioral questions. They didn't give any feedback.
- ly October 21, 2017
the questions were not hard at all.
one round, I only got asked behavioral questions for 45 mins. really not that much to say
disappointed| Flag | PURGE 0 Answers Is Amazon Joking Around?
Amazon is known for its tough tech screening rounds but even if you nail those technical question with best possible solution, are you getting screwed??
- hprem991 August 04, 2017
Before this experience, I would have said NO but now it is looking different..
I was being picked up by their recruiter and asked to present myself for phone screening as they liked my experience (thats what they said ).
Now, I wouldnt mind.. being the fact that I am doing great in what I am doing.. its just a 1 hour call.
Well, call lasted for like 55 mins.. Was asked 2 algorithmic questions with code and follow ups and some pretty team / experience related question..
I nailed the tech rounds so much that the interviewer said, I got questions done with most optimal solutions and of course before time.
So, if they liked my experiences ( thats what they said they called me at first place).. Did they rejected me for same experience or Amazon interview has become a joking ground now?
Any thoughts??| Flag | PURGE 1 Answer Design a FIDS(Flight Information Display System)
1. Consider most important classes & ignore Interfaces as of now
- AD August 04, 2017
2. FIDS is not about reservation system but the dasboard to display
3. the information will look like:
DEPARTURES
----------------------
Attributes:
STD, Airline,Flight#,Destination/Via,CheckInCounter#,Gate,Status,ETD
Values :
12:50,KingFisher,6E352,Hyderabad,A-B,23,Check-In Open,13:15
ARRIVALS
-----------------------
Attributes:
STA,Airline,Flight#,Destination/Via,Gate,Status,ETA
Values :
12:50,KingFisher,6E352,UK/Mumbai,Terminal2,Landed,13:15| Flag | PURGE 0 Answers Minheap: TLE
The following is my code for MinHeap. But it is showing TLE for some input. Can someone please help me figure out where?
- ranjani4ever July 14, 2017
#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
using namespace std;
void swap(int *a,int *b){
int temp=*a;
*a=*b;
*b=temp;
return;
}
void heapify(vector<int> &heap,int index)
{
int length=heap.size();
int min=index;
int left=(index<<1)+1;
int right=(index<<1)+2;
if(left<length&&heap[left]<heap[min])
min=left;
if(right<length&&heap[right]<heap[min])
min=right;
if(min!=index)
{
swap(&heap[index],&heap[min]);
heapify(heap,min);
}
}
int main() {
int t,n;
string op;
scanf("%d",&t);
vector<int> heap;
while(t--) {
cin>>op;
//cout<<"Currently analysing"<<op<<"\n";
if(op=="insert") {
scanf("%d",&n);
heap.push_back(n);
int i=heap.size()-1;
while (i!=0&&heap[(i-1)>>1]>heap[i])
{
swap(&heap[i], &heap[(i-1)>>1]);
i =(i-1)/2;
}
}
else if(op=="getMin") {
if(heap.size()>0)
printf("%d\n",heap[0]);
else
printf("Empty\n");
/*for(int i=0;i<heap.size();i++)
cout<<heap[i]<<" ";
cout<<"\n";*/
}
else {
if(heap.size()>0)
{
heap.erase(heap.begin());
heapify(heap,0);
}
}
}
return 0;
}| Flag | PURGE 0 Answers Amazon question
At Amazon.com, users log in and access random pages numbered as 1,2,3… Given at any time, you need to tell the most popular sequence of 3 pages visited by users.
- yeswanth June 28, 2017
Eg.
At some time t,
U1: P1, P2, P3, P8, P1, P2
U2: P8, P1, P2
O/P: P8, P1, P2
At time t+1, say
U1: P1, P2, P3, P8, P1, P2, P3
U2: P8, P3, P2
O/P: P1, P2, P3| Flag | PURGE 0 Answers Question
There are around 40 million files in a directory which needs to be transferred to another system via FTP in order of oldest file first. What's the ideal way to iterate over files and store it in a data structure from where it can be transferred?
- anjesh June 12, 2017| Flag | PURGE 0 Answers qwrew
A mission-critical production system has n stages that have to be performed sequentially; stage
- tanvirmahmud201505039 June 08, 2017
i is performed by machine Mi. Each machine Mi has a probability ri of functioning reliably and
a probability 1 − ri of failing (and the failures are independent). Therefore, if we implement
each stage with a single machine, the probability that the whole system works is r1 · r2 · · · rn.
To improve this probability we add redundancy, by having mi copies of the machine Mi that
performs stage i. The probability that all mi copies fail simultaneously is only (1 − ri)mi, so the
probability that stage i is completed correctly is 1 − (1 − ri)mi and the probability that the whole
system works is Qni=1(1 − (1 − ri)mi). Each machine Mi has a cost ci, and there is a total budget
B to buy machines. (Assume that B and ci are positive integers.)
Given the probabilities r1, . . . , rn, the costs c1, . . . , cn, and the budget B, find the redundancies
m1, . . . , mn that are within the available budget and that maximize the probability that the
system works correctly| Flag | PURGE 0 Answers Designing a data-structure
We need to implement a data-structure for following functions
- arnav251035 May 29, 2017
Insert X : Insert an element X into the set.
Delete X : Delete an element X from the set. It is guaranteed that such X always exist in the data structure.
Mean : Report Mean of the elements present in the data set. It is guaranteed that data structure will not be empty at this query.
Mode : Report Mode of the elements present in the data set. It is guaranteed that data structure will not be empty at this query.
Median : Report Median of the elements present in the data set. It is guaranteed that data structure will not be empty at this query
I had created a linked list of the values, and like insertion sort I inserted the elements in the Linked List. Deletion was also the same as deletion in Linked List. Mean I calculated on the run as and when the values came. For mode I traversed the whole linked list to see which element occurs the most. Median was the middle element in the linked list.
I know there is an efficient algorithm to calculate median on the run using two heaps (min and max) but calculating mode was the biggest problem I faced. The number of queries ranged to 10^5 and the time limit was given 3 secs. Had a TLE error| Flag | PURGE