Your browser (Unknown 0) is no longer supported. Some parts of the website may not work correctly. Please update your browser.

UPCOMING CHALLENGES:

CURRENT CHALLENGES:

Future Mobility

PAST CHALLENGES

Grand Challenge

Decoding Master

Digital Gold

Selenium 2018

Germanium 2018

Gallium 2018

Zinc 2018

Cuprum 2018

Cutting Complexity

Nickel 2018

Cobaltum 2018

Ferrum 2018

Manganum 2017

Chromium 2017

Vanadium 2016

Titanium 2016

Scandium 2016

Calcium 2015

Kalium 2015

Argon 2015

Chlorum 2014

Sulphur 2014

Phosphorus 2014

Silicium 2014

Aluminium 2014

Magnesium 2014

Natrium 2014

Neon 2014

Fluorum 2014

Oxygenium 2014

Nitrogenium 2013

Carbo 2013

Boron 2013

Beryllium 2013

Lithium 2013

Helium 2013

Hydrogenium 2013

Omega 2013

Psi 2012

Chi 2012

Phi 2012

Upsilon 2012

Tau 2012

Sigma 2012

Rho 2012

Pi 2012

Omicron 2012

Xi 2012

Nu 2011

Mu 2011

Lambda 2011

Kappa 2011

Iota 2011

Theta 2011

Eta 2011

Zeta 2011

Epsilon 2011

Delta 2011

Gamma 2011

Beta 2010

Alpha 2010

ambitious

For each node in a tree find the sum of distances to all other nodes.

Programming language:
Spoken language:

A computer network consisting of N routers and N−1 links connecting them is given. Routers are labeled with distinct integers within the range [0..(N−1)]. Links connect routers in such a way that each distinct pair of routers is connected either by a direct link or through a path consisting of direct links. There is exactly one way to reach any router from another and the number of direct links that must be traversed is called the *distance* between these two routers. For example, consider the following network consisting of ten routers and nine links:

Routers 2 and 4 are connected directly, so the distance between them is 1. Routers 4 and 7 are connected through a path consisting of direct links 4−0, 0−9 and 9−7; hence the distance between them is 3.

The location of a router in the network determines how quickly a packet dispatched by that router can reach other routers. The *peripherality* of a router is the average distance to all other routers on the network. For example, the peripherality of router 4 in the network shown above is 2.11, because:

distance to 0: 1 distance to 1: 3 distance to 2: 1 distance to 3: 3 distance to 5: 1 distance to 6: 3 distance to 7: 3 distance to 8: 2 distance to 9: 2 average: 19/9 = 2.11

The peripherality of router 0 is 1.66 and no other router has lower peripherality.

Write a function

int solution(int T[], int N);

that, given a non-empty array T consisting of N integers describing a network of N routers and N−1 links, returns the label of the router that has minimum peripherality. If there is more than one router that has minimum peripherality, the function should return the lowest label.

Array T describes a network of routers as follows:

- if T[P] = Q and P ≠ Q, then there is a direct link between routers P and Q.

For example, given the following array T consisting of ten elements:

the function should return 0, because this array describes the network shown above and router 0 has minimum peripherality.

Write an ** efficient** algorithm for the following assumptions:

- N is an integer within the range [1..100,000];
- each element of array T is an integer within the range [0..(N−1);
- there is exactly one (possibly indirect) connection between any two distinct routers.

Copyright 2009–2018 by Codility Limited. All Rights Reserved. Unauthorized copying, publication or disclosure prohibited.

A computer network consisting of N routers and N−1 links connecting them is given. Routers are labeled with distinct integers within the range [0..(N−1)]. Links connect routers in such a way that each distinct pair of routers is connected either by a direct link or through a path consisting of direct links. There is exactly one way to reach any router from another and the number of direct links that must be traversed is called the *distance* between these two routers. For example, consider the following network consisting of ten routers and nine links:

Routers 2 and 4 are connected directly, so the distance between them is 1. Routers 4 and 7 are connected through a path consisting of direct links 4−0, 0−9 and 9−7; hence the distance between them is 3.

The location of a router in the network determines how quickly a packet dispatched by that router can reach other routers. The *peripherality* of a router is the average distance to all other routers on the network. For example, the peripherality of router 4 in the network shown above is 2.11, because:

distance to 0: 1 distance to 1: 3 distance to 2: 1 distance to 3: 3 distance to 5: 1 distance to 6: 3 distance to 7: 3 distance to 8: 2 distance to 9: 2 average: 19/9 = 2.11

The peripherality of router 0 is 1.66 and no other router has lower peripherality.

Write a function

int solution(vector<int> &T);

that, given a non-empty array T consisting of N integers describing a network of N routers and N−1 links, returns the label of the router that has minimum peripherality. If there is more than one router that has minimum peripherality, the function should return the lowest label.

Array T describes a network of routers as follows:

- if T[P] = Q and P ≠ Q, then there is a direct link between routers P and Q.

For example, given the following array T consisting of ten elements:

the function should return 0, because this array describes the network shown above and router 0 has minimum peripherality.

Write an ** efficient** algorithm for the following assumptions:

- N is an integer within the range [1..100,000];
- each element of array T is an integer within the range [0..(N−1);
- there is exactly one (possibly indirect) connection between any two distinct routers.

Copyright 2009–2018 by Codility Limited. All Rights Reserved. Unauthorized copying, publication or disclosure prohibited.

A computer network consisting of N routers and N−1 links connecting them is given. Routers are labeled with distinct integers within the range [0..(N−1)]. Links connect routers in such a way that each distinct pair of routers is connected either by a direct link or through a path consisting of direct links. There is exactly one way to reach any router from another and the number of direct links that must be traversed is called the *distance* between these two routers. For example, consider the following network consisting of ten routers and nine links:

Routers 2 and 4 are connected directly, so the distance between them is 1. Routers 4 and 7 are connected through a path consisting of direct links 4−0, 0−9 and 9−7; hence the distance between them is 3.

The location of a router in the network determines how quickly a packet dispatched by that router can reach other routers. The *peripherality* of a router is the average distance to all other routers on the network. For example, the peripherality of router 4 in the network shown above is 2.11, because:

distance to 0: 1 distance to 1: 3 distance to 2: 1 distance to 3: 3 distance to 5: 1 distance to 6: 3 distance to 7: 3 distance to 8: 2 distance to 9: 2 average: 19/9 = 2.11

The peripherality of router 0 is 1.66 and no other router has lower peripherality.

Write a function

class Solution { public int solution(int[] T); }

that, given a non-empty array T consisting of N integers describing a network of N routers and N−1 links, returns the label of the router that has minimum peripherality. If there is more than one router that has minimum peripherality, the function should return the lowest label.

Array T describes a network of routers as follows:

- if T[P] = Q and P ≠ Q, then there is a direct link between routers P and Q.

For example, given the following array T consisting of ten elements:

the function should return 0, because this array describes the network shown above and router 0 has minimum peripherality.

Write an ** efficient** algorithm for the following assumptions:

- N is an integer within the range [1..100,000];
- each element of array T is an integer within the range [0..(N−1);
- there is exactly one (possibly indirect) connection between any two distinct routers.

Copyright 2009–2018 by Codility Limited. All Rights Reserved. Unauthorized copying, publication or disclosure prohibited.

*distance* between these two routers. For example, consider the following network consisting of ten routers and nine links:

*peripherality* of a router is the average distance to all other routers on the network. For example, the peripherality of router 4 in the network shown above is 2.11, because:

distance to 0: 1 distance to 1: 3 distance to 2: 1 distance to 3: 3 distance to 5: 1 distance to 6: 3 distance to 7: 3 distance to 8: 2 distance to 9: 2 average: 19/9 = 2.11

The peripherality of router 0 is 1.66 and no other router has lower peripherality.

Write a function

func Solution(T []int) int

Array T describes a network of routers as follows:

- if T[P] = Q and P ≠ Q, then there is a direct link between routers P and Q.

For example, given the following array T consisting of ten elements:

Write an ** efficient** algorithm for the following assumptions:

- N is an integer within the range [1..100,000];
- each element of array T is an integer within the range [0..(N−1);
- there is exactly one (possibly indirect) connection between any two distinct routers.

*distance* between these two routers. For example, consider the following network consisting of ten routers and nine links:

*peripherality* of a router is the average distance to all other routers on the network. For example, the peripherality of router 4 in the network shown above is 2.11, because:

distance to 0: 1 distance to 1: 3 distance to 2: 1 distance to 3: 3 distance to 5: 1 distance to 6: 3 distance to 7: 3 distance to 8: 2 distance to 9: 2 average: 19/9 = 2.11

The peripherality of router 0 is 1.66 and no other router has lower peripherality.

Write a function

class Solution { public int solution(int[] T); }

Array T describes a network of routers as follows:

- if T[P] = Q and P ≠ Q, then there is a direct link between routers P and Q.

For example, given the following array T consisting of ten elements:

Write an ** efficient** algorithm for the following assumptions:

- N is an integer within the range [1..100,000];
- each element of array T is an integer within the range [0..(N−1);
- there is exactly one (possibly indirect) connection between any two distinct routers.

*distance* between these two routers. For example, consider the following network consisting of ten routers and nine links:

*peripherality* of a router is the average distance to all other routers on the network. For example, the peripherality of router 4 in the network shown above is 2.11, because:

distance to 0: 1 distance to 1: 3 distance to 2: 1 distance to 3: 3 distance to 5: 1 distance to 6: 3 distance to 7: 3 distance to 8: 2 distance to 9: 2 average: 19/9 = 2.11

The peripherality of router 0 is 1.66 and no other router has lower peripherality.

Write a function

function solution(T);

Array T describes a network of routers as follows:

- if T[P] = Q and P ≠ Q, then there is a direct link between routers P and Q.

For example, given the following array T consisting of ten elements:

Write an ** efficient** algorithm for the following assumptions:

- N is an integer within the range [1..100,000];
- each element of array T is an integer within the range [0..(N−1);
- there is exactly one (possibly indirect) connection between any two distinct routers.

*distance* between these two routers. For example, consider the following network consisting of ten routers and nine links:

*peripherality* of a router is the average distance to all other routers on the network. For example, the peripherality of router 4 in the network shown above is 2.11, because:

distance to 0: 1 distance to 1: 3 distance to 2: 1 distance to 3: 3 distance to 5: 1 distance to 6: 3 distance to 7: 3 distance to 8: 2 distance to 9: 2 average: 19/9 = 2.11

The peripherality of router 0 is 1.66 and no other router has lower peripherality.

Write a function

function solution(T)

Array T describes a network of routers as follows:

- if T[P] = Q and P ≠ Q, then there is a direct link between routers P and Q.

For example, given the following array T consisting of ten elements:

Write an ** efficient** algorithm for the following assumptions:

- N is an integer within the range [1..100,000];
- each element of array T is an integer within the range [0..(N−1);
- there is exactly one (possibly indirect) connection between any two distinct routers.

Note: All arrays in this task are zero-indexed, unlike the common Lua convention. You can use `#A` to get the length of the array A.

*distance* between these two routers. For example, consider the following network consisting of ten routers and nine links:

*peripherality* of a router is the average distance to all other routers on the network. For example, the peripherality of router 4 in the network shown above is 2.11, because:

distance to 0: 1 distance to 1: 3 distance to 2: 1 distance to 3: 3 distance to 5: 1 distance to 6: 3 distance to 7: 3 distance to 8: 2 distance to 9: 2 average: 19/9 = 2.11

The peripherality of router 0 is 1.66 and no other router has lower peripherality.

Write a function

int solution(NSMutableArray *T);

Array T describes a network of routers as follows:

- if T[P] = Q and P ≠ Q, then there is a direct link between routers P and Q.

For example, given the following array T consisting of ten elements:

Write an ** efficient** algorithm for the following assumptions:

- N is an integer within the range [1..100,000];
- each element of array T is an integer within the range [0..(N−1);
- there is exactly one (possibly indirect) connection between any two distinct routers.

*distance* between these two routers. For example, consider the following network consisting of ten routers and nine links:

*peripherality* of a router is the average distance to all other routers on the network. For example, the peripherality of router 4 in the network shown above is 2.11, because:

distance to 0: 1 distance to 1: 3 distance to 2: 1 distance to 3: 3 distance to 5: 1 distance to 6: 3 distance to 7: 3 distance to 8: 2 distance to 9: 2 average: 19/9 = 2.11

The peripherality of router 0 is 1.66 and no other router has lower peripherality.

Write a function

function solution(T: array of longint; N: longint): longint;

Array T describes a network of routers as follows:

- if T[P] = Q and P ≠ Q, then there is a direct link between routers P and Q.

For example, given the following array T consisting of ten elements:

Write an ** efficient** algorithm for the following assumptions:

- N is an integer within the range [1..100,000];
- each element of array T is an integer within the range [0..(N−1);
- there is exactly one (possibly indirect) connection between any two distinct routers.

*distance* between these two routers. For example, consider the following network consisting of ten routers and nine links:

*peripherality* of a router is the average distance to all other routers on the network. For example, the peripherality of router 4 in the network shown above is 2.11, because:

distance to 0: 1 distance to 1: 3 distance to 2: 1 distance to 3: 3 distance to 5: 1 distance to 6: 3 distance to 7: 3 distance to 8: 2 distance to 9: 2 average: 19/9 = 2.11

The peripherality of router 0 is 1.66 and no other router has lower peripherality.

Write a function

function solution($T);

Array T describes a network of routers as follows:

- if T[P] = Q and P ≠ Q, then there is a direct link between routers P and Q.

For example, given the following array T consisting of ten elements:

Write an ** efficient** algorithm for the following assumptions:

- N is an integer within the range [1..100,000];
- each element of array T is an integer within the range [0..(N−1);
- there is exactly one (possibly indirect) connection between any two distinct routers.

*distance* between these two routers. For example, consider the following network consisting of ten routers and nine links:

*peripherality* of a router is the average distance to all other routers on the network. For example, the peripherality of router 4 in the network shown above is 2.11, because:

distance to 0: 1 distance to 1: 3 distance to 2: 1 distance to 3: 3 distance to 5: 1 distance to 6: 3 distance to 7: 3 distance to 8: 2 distance to 9: 2 average: 19/9 = 2.11

The peripherality of router 0 is 1.66 and no other router has lower peripherality.

Write a function

sub solution { my (@T)=@_; ... }

Array T describes a network of routers as follows:

- if T[P] = Q and P ≠ Q, then there is a direct link between routers P and Q.

For example, given the following array T consisting of ten elements:

Write an ** efficient** algorithm for the following assumptions:

- N is an integer within the range [1..100,000];
- each element of array T is an integer within the range [0..(N−1);
- there is exactly one (possibly indirect) connection between any two distinct routers.

*distance* between these two routers. For example, consider the following network consisting of ten routers and nine links:

*peripherality* of a router is the average distance to all other routers on the network. For example, the peripherality of router 4 in the network shown above is 2.11, because:

distance to 0: 1 distance to 1: 3 distance to 2: 1 distance to 3: 3 distance to 5: 1 distance to 6: 3 distance to 7: 3 distance to 8: 2 distance to 9: 2 average: 19/9 = 2.11

The peripherality of router 0 is 1.66 and no other router has lower peripherality.

Write a function

def solution(T)

Array T describes a network of routers as follows:

- if T[P] = Q and P ≠ Q, then there is a direct link between routers P and Q.

For example, given the following array T consisting of ten elements:

Write an ** efficient** algorithm for the following assumptions:

- N is an integer within the range [1..100,000];
- each element of array T is an integer within the range [0..(N−1);
- there is exactly one (possibly indirect) connection between any two distinct routers.

*distance* between these two routers. For example, consider the following network consisting of ten routers and nine links:

*peripherality* of a router is the average distance to all other routers on the network. For example, the peripherality of router 4 in the network shown above is 2.11, because:

distance to 0: 1 distance to 1: 3 distance to 2: 1 distance to 3: 3 distance to 5: 1 distance to 6: 3 distance to 7: 3 distance to 8: 2 distance to 9: 2 average: 19/9 = 2.11

The peripherality of router 0 is 1.66 and no other router has lower peripherality.

Write a function

def solution(t)

Array T describes a network of routers as follows:

- if T[P] = Q and P ≠ Q, then there is a direct link between routers P and Q.

For example, given the following array T consisting of ten elements:

Write an ** efficient** algorithm for the following assumptions:

- N is an integer within the range [1..100,000];
- each element of array T is an integer within the range [0..(N−1);
- there is exactly one (possibly indirect) connection between any two distinct routers.

*distance* between these two routers. For example, consider the following network consisting of ten routers and nine links:

*peripherality* of a router is the average distance to all other routers on the network. For example, the peripherality of router 4 in the network shown above is 2.11, because:

distance to 0: 1 distance to 1: 3 distance to 2: 1 distance to 3: 3 distance to 5: 1 distance to 6: 3 distance to 7: 3 distance to 8: 2 distance to 9: 2 average: 19/9 = 2.11

The peripherality of router 0 is 1.66 and no other router has lower peripherality.

Write a function

object Solution { def solution(t: Array[Int]): Int }

Array T describes a network of routers as follows:

- if T[P] = Q and P ≠ Q, then there is a direct link between routers P and Q.

For example, given the following array T consisting of ten elements:

Write an ** efficient** algorithm for the following assumptions:

- N is an integer within the range [1..100,000];
- each element of array T is an integer within the range [0..(N−1);
- there is exactly one (possibly indirect) connection between any two distinct routers.

*distance* between these two routers. For example, consider the following network consisting of ten routers and nine links:

*peripherality* of a router is the average distance to all other routers on the network. For example, the peripherality of router 4 in the network shown above is 2.11, because:

distance to 0: 1 distance to 1: 3 distance to 2: 1 distance to 3: 3 distance to 5: 1 distance to 6: 3 distance to 7: 3 distance to 8: 2 distance to 9: 2 average: 19/9 = 2.11

The peripherality of router 0 is 1.66 and no other router has lower peripherality.

Write a function

public func solution(inout T : [Int]) -> Int

Array T describes a network of routers as follows:

- if T[P] = Q and P ≠ Q, then there is a direct link between routers P and Q.

For example, given the following array T consisting of ten elements:

Write an ** efficient** algorithm for the following assumptions:

- N is an integer within the range [1..100,000];
- each element of array T is an integer within the range [0..(N−1);
- there is exactly one (possibly indirect) connection between any two distinct routers.

*distance* between these two routers. For example, consider the following network consisting of ten routers and nine links:

*peripherality* of a router is the average distance to all other routers on the network. For example, the peripherality of router 4 in the network shown above is 2.11, because:

distance to 0: 1 distance to 1: 3 distance to 2: 1 distance to 3: 3 distance to 5: 1 distance to 6: 3 distance to 7: 3 distance to 8: 2 distance to 9: 2 average: 19/9 = 2.11

The peripherality of router 0 is 1.66 and no other router has lower peripherality.

Write a function

public func solution(_ T : inout [Int]) -> Int

Array T describes a network of routers as follows:

- if T[P] = Q and P ≠ Q, then there is a direct link between routers P and Q.

For example, given the following array T consisting of ten elements:

Write an ** efficient** algorithm for the following assumptions:

- N is an integer within the range [1..100,000];
- each element of array T is an integer within the range [0..(N−1);
- there is exactly one (possibly indirect) connection between any two distinct routers.

*distance* between these two routers. For example, consider the following network consisting of ten routers and nine links:

*peripherality* of a router is the average distance to all other routers on the network. For example, the peripherality of router 4 in the network shown above is 2.11, because:

distance to 0: 1 distance to 1: 3 distance to 2: 1 distance to 3: 3 distance to 5: 1 distance to 6: 3 distance to 7: 3 distance to 8: 2 distance to 9: 2 average: 19/9 = 2.11

The peripherality of router 0 is 1.66 and no other router has lower peripherality.

Write a function

Private Function solution(T As Integer()) As Integer

Array T describes a network of routers as follows:

- if T[P] = Q and P ≠ Q, then there is a direct link between routers P and Q.

For example, given the following array T consisting of ten elements:

Write an ** efficient** algorithm for the following assumptions:

- N is an integer within the range [1..100,000];
- each element of array T is an integer within the range [0..(N−1);
- there is exactly one (possibly indirect) connection between any two distinct routers.

Information about upcoming challenges, solutions and lessons directly in your inbox.

© 2009–2018 Codility Ltd., registered in England and Wales (No. 7048726). VAT ID GB981191408. Registered office: 107 Cheapside, London EC2V 6DN