Tasks Details
medium
Find the minimal average of any slice containing at least two elements.
Task Score
0%
Correctness
0%
Performance
0%
A non-empty array A consisting of N integers is given. A pair of integers (P, Q), such that 0 ≤ P < Q < N, is called a slice of array A (notice that the slice contains at least two elements). The average of a slice (P, Q) is the sum of A[P] + A[P + 1] + ... + A[Q] divided by the length of the slice. To be precise, the average equals (A[P] + A[P + 1] + ... + A[Q]) / (Q − P + 1).
For example, array A such that:
A[0] = 4 A[1] = 2 A[2] = 2 A[3] = 5 A[4] = 1 A[5] = 5 A[6] = 8contains the following example slices:
- slice (1, 2), whose average is (2 + 2) / 2 = 2;
- slice (3, 4), whose average is (5 + 1) / 2 = 3;
- slice (1, 4), whose average is (2 + 2 + 5 + 1) / 4 = 2.5.
The goal is to find the starting position of a slice whose average is minimal.
Write a function:
function solution(A);
that, given a non-empty array A consisting of N integers, returns the starting position of the slice with the minimal average. If there is more than one slice with a minimal average, you should return the smallest starting position of such a slice.
For example, given array A such that:
A[0] = 4 A[1] = 2 A[2] = 2 A[3] = 5 A[4] = 1 A[5] = 5 A[6] = 8the function should return 1, as explained above.
Write an efficient algorithm for the following assumptions:
- N is an integer within the range [2..100,000];
- each element of array A is an integer within the range [−10,000..10,000].
Copyright 2009–2025 by Codility Limited. All Rights Reserved. Unauthorized copying, publication or disclosure prohibited.
Solution
Programming language used JavaScript
Time spent on task 15 minutes
Notes
not defined yet
Task timeline
Code: 01:56:34 UTC,
js,
verify,
result: Failed
// you can write to stdout for debugging purposes, e.g.
// console.log('this is a debug message');
function solution(A) {
// write your code in JavaScript (Node.js 6.4.0)
let total = 0;
let average = 0;
let i = 0;
let max_value = 0;
let rt = 0;
for(i in A) {
total +=A[i];
if(max_value < A[i]) {
max_value = A[i];
}
}
average = total/A.length;
for(i=0;i<A.length;i++) {
if(A[i] < A[i+1] && A[i] < average ) {
rt = i;
}
}
return rt;
}
Analysis
expand all
Example tests
1.
0.072 s
WRONG ANSWER,
got 4 expected 1
Code: 01:57:57 UTC,
js,
verify,
result: Failed
// you can write to stdout for debugging purposes, e.g.
// console.log('this is a debug message');
function solution(A) {
// write your code in JavaScript (Node.js 6.4.0)
let total = 0;
let average = 0;
let i = 0;
let max_value = 0;
let rt = 0;
for(i in A) {
total +=A[i];
}
average = total/A.length;
for(i=0;i<A.length;i++) {
if(A[i] < A[i+1] && A[i] < average && A[i+1] < average ) {
rt = i;
}
}
return rt;
}
Analysis
expand all
Example tests
1.
0.072 s
WRONG ANSWER,
got 0 expected 1
Code: 01:58:09 UTC,
js,
verify,
result: Failed
// you can write to stdout for debugging purposes, e.g.
// console.log('this is a debug message');
function solution(A) {
// write your code in JavaScript (Node.js 6.4.0)
let total = 0;
let average = 0;
let i = 0;
let max_value = 0;
let rt = 0;
for(i in A) {
total +=A[i];
}
average = total/A.length;
for(i=0;i<A.length;i++) {
if(A[i] =< A[i+1] && A[i] < average && A[i+1] < average ) {
rt = i;
}
}
return rt;
}
Analysis
expand all
Example tests
1.
0.072 s
RUNTIME ERROR,
tested program terminated unexpectedly
stderr:
solution.js:17
if(A[i] =< A[i+1] && A[i] < average && A[i+1] < average ) {
^
SyntaxError: Unexpected token <
at Object.exports.runInNewContext (vm.js:71:16)
at getSolution (/tmp/exec.js:392:29)
at Promise.resolve.then (/tmp/exec.js:426:34)
at process._tickCallback (internal/process/next_tick.js:103:7)
at Module.runMain (module.js:592:11)
at run (bootstrap_node.js:394:7)
at startup (bootstrap_node.js:149:9)
at bootstrap_node.js:509:3
Code: 01:58:18 UTC,
js,
verify,
result: Passed
// you can write to stdout for debugging purposes, e.g.
// console.log('this is a debug message');
function solution(A) {
// write your code in JavaScript (Node.js 6.4.0)
let total = 0;
let average = 0;
let i = 0;
let max_value = 0;
let rt = 0;
for(i in A) {
total +=A[i];
}
average = total/A.length;
for(i=0;i<A.length;i++) {
if(A[i] <= A[i+1] && A[i] < average && A[i+1] < average ) {
rt = i;
}
}
return rt;
}
Analysis
Code: 01:58:53 UTC,
js,
verify,
result: Passed
// you can write to stdout for debugging purposes, e.g.
// console.log('this is a debug message');
function solution(A) {
// write your code in JavaScript (Node.js 6.4.0)
let total = 0;
let average = 0;
let i = 0;
let max_value = 0;
let rt = 0;
for(i in A) {
total +=A[i];
}
average = total/A.length;
for(i=0;i<A.length;i++) {
if(A[i] <= A[i+1] && A[i] < average && A[i+1] < average ) {
rt = i;
}
}
return rt;
}
User test case 1:
[1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
Analysis
Code: 01:59:19 UTC,
js,
verify,
result: Passed
// you can write to stdout for debugging purposes, e.g.
// console.log('this is a debug message');
function solution(A) {
// write your code in JavaScript (Node.js 6.4.0)
let total = 0;
let average = 0;
let i = 0;
let max_value = 0;
let rt = 0;
for(i in A) {
total +=A[i];
}
average = total/A.length;
console.log(average);
for(i=0;i<A.length;i++) {
if(A[i] <= A[i+1] && A[i] < average && A[i+1] < average ) {
rt = i;
}
}
return rt;
}
User test case 1:
[1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
Analysis
Code: 02:02:23 UTC,
js,
verify,
result: Passed
// you can write to stdout for debugging purposes, e.g.
// console.log('this is a debug message');
function solution(A) {
// write your code in JavaScript (Node.js 6.4.0)
let total = 0;
let average = 0;
let i = 0;
let rt = 0;
for(i in A) {
total +=A[i];
if(rt < A[i]) { rt = A[i]; }
}
average = total/A.length;
console.log(average);
for(i=0;i<A.length;i++) {
if(A[i] <= A[i+1] && A[i] < average && A[i+1] < average && rt > A[i]) {
rt = i;
}
}
return rt;
}
User test case 1:
[1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
Analysis
Code: 02:02:49 UTC,
js,
verify,
result: Passed
// you can write to stdout for debugging purposes, e.g.
// console.log('this is a debug message');
function solution(A) {
// write your code in JavaScript (Node.js 6.4.0)
let total = 0;
let average = 0;
let i = 0;
let rt = 0;
for(i in A) {
total +=A[i];
if(rt < A[i]) { rt = A[i]; }
}
average = total/A.length;
console.log(average);
for(i=0;i<A.length;i++) {
if(A[i] <= A[i+1] && A[i] < average && A[i+1] < average && rt > A[i]) {
rt = i;
}
}
return rt;
}
User test case 1:
[1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
User test case 2:
[9, 8, 7, 6, 5]
Analysis
expand all
User tests
1.
0.072 s
OK
function result: 0
function result: 0
stdout:
5.5
1.
0.072 s
OK
function result: 9
function result: 9
stdout:
7
Code: 02:05:01 UTC,
js,
verify,
result: Passed
// you can write to stdout for debugging purposes, e.g.
// console.log('this is a debug message');
function solution(A) {
// write your code in JavaScript (Node.js 6.4.0)
let total = 0;
let average = 0;
let i = 0;
let rt = 0;
for(i in A) {
total +=A[i];
if(rt < A[i]) { rt = A[i]; }
}
average = total/A.length;
console.log(average);
for(i=0;i<A.length;i++) {
if(
//A[i] <= A[i+1] &&
A[i] < average && A[i+1] < average
//&& rt > A[i]
) {
rt = i;
}
}
return rt;
}
User test case 1:
[1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
User test case 2:
[9, 8, 7, 6, 5]
Analysis
expand all
User tests
1.
0.072 s
OK
function result: 3
function result: 3
stdout:
5.5
1.
0.072 s
OK
function result: 3
function result: 3
stdout:
7
Code: 02:05:38 UTC,
js,
verify,
result: Failed
// you can write to stdout for debugging purposes, e.g.
// console.log('this is a debug message');
function solution(A) {
// write your code in JavaScript (Node.js 6.4.0)
let total = 0;
let average = 0;
let i = 0;
let rt = 0;
for(i in A) {
total +=A[i];
if(rt < A[i]) { rt = A[i]; }
}
average = total/A.length;
console.log(average);
for(i=0;i<A.length;i++) {
if(
//A[i] <= A[i+1] &&
A[i] < average && A[i+1] < average
&& rt < A[i]
) {
rt = i;
}
}
return rt;
}
User test case 1:
[1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
User test case 2:
[9, 8, 7, 6, 5]
Analysis
expand all
Example tests
1.
0.072 s
WRONG ANSWER,
got 8 expected 1
stdout:
3.857142857142857
expand all
User tests
1.
0.072 s
OK
function result: 10
function result: 10
stdout:
5.5
1.
0.072 s
OK
function result: 9
function result: 9
stdout:
7
Code: 02:05:48 UTC,
js,
verify,
result: Passed
// you can write to stdout for debugging purposes, e.g.
// console.log('this is a debug message');
function solution(A) {
// write your code in JavaScript (Node.js 6.4.0)
let total = 0;
let average = 0;
let i = 0;
let rt = 0;
for(i in A) {
total +=A[i];
//if(rt < A[i]) { rt = A[i]; }
}
average = total/A.length;
console.log(average);
for(i=0;i<A.length;i++) {
if(
//A[i] <= A[i+1] &&
A[i] < average && A[i+1] < average
&& rt < A[i]
) {
rt = i;
}
}
return rt;
}
User test case 1:
[1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
User test case 2:
[9, 8, 7, 6, 5]
Analysis
expand all
User tests
1.
0.072 s
OK
function result: 3
function result: 3
stdout:
5.5
1.
0.072 s
OK
function result: 3
function result: 3
stdout:
7
Code: 02:06:10 UTC,
js,
verify,
result: Failed
// you can write to stdout for debugging purposes, e.g.
// console.log('this is a debug message');
function solution(A) {
// write your code in JavaScript (Node.js 6.4.0)
let total = 0;
let average = 0;
let i = 0;
let rt = 0;
for(i in A) {
total +=A[i];
//if(rt < A[i]) { rt = A[i]; }
}
average = total/A.length;
console.log(average);
for(i=0;i<A.length;i++) {
if(
//A[i] <= A[i+1] &&
A[i] < average && A[i+1] < average
&& rt > A[i]
) {
rt = i;
}
}
return rt;
}
User test case 1:
[1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
User test case 2:
[9, 8, 7, 6, 5]
Analysis
expand all
Example tests
1.
0.076 s
WRONG ANSWER,
got 0 expected 1
stdout:
3.857142857142857
expand all
User tests
1.
0.072 s
OK
function result: 0
function result: 0
stdout:
5.5
1.
0.076 s
OK
function result: 0
function result: 0
stdout:
7
Code: 02:06:21 UTC,
js,
verify,
result: Passed
// you can write to stdout for debugging purposes, e.g.
// console.log('this is a debug message');
function solution(A) {
// write your code in JavaScript (Node.js 6.4.0)
let total = 0;
let average = 0;
let i = 0;
let rt = 0;
for(i in A) {
total +=A[i];
if(rt < A[i]) { rt = A[i]; }
}
average = total/A.length;
console.log(average);
for(i=0;i<A.length;i++) {
if(
//A[i] <= A[i+1] &&
A[i] < average && A[i+1] < average
&& rt > A[i]
) {
rt = i;
}
}
return rt;
}
User test case 1:
[1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
User test case 2:
[9, 8, 7, 6, 5]
Analysis
expand all
User tests
1.
0.072 s
OK
function result: 0
function result: 0
stdout:
5.5
1.
0.068 s
OK
function result: 3
function result: 3
stdout:
7
Code: 02:07:09 UTC,
js,
verify,
result: Passed
// you can write to stdout for debugging purposes, e.g.
// console.log('this is a debug message');
function solution(A) {
// write your code in JavaScript (Node.js 6.4.0)
let total = 0;
let average = 0;
let i = 0;
let rt = 0;
for(i in A) {
total +=A[i];
if(rt < A[i]) { rt = A[i]; }
}
average = total/A.length;
for(i=0;i<A.length;i++) {
if(A[i] < average
&& A[i+1] < average
&& rt > A[i]) {
rt = i;
}
}
return rt;
}
User test case 1:
[1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
User test case 2:
[9, 8, 7, 6, 5]
Analysis
Code: 02:07:12 UTC,
js,
final,
score:
0
// you can write to stdout for debugging purposes, e.g.
// console.log('this is a debug message');
function solution(A) {
// write your code in JavaScript (Node.js 6.4.0)
let total = 0;
let average = 0;
let i = 0;
let rt = 0;
for(i in A) {
total +=A[i];
if(rt < A[i]) { rt = A[i]; }
}
average = total/A.length;
for(i=0;i<A.length;i++) {
if(A[i] < average
&& A[i+1] < average
&& rt > A[i]) {
rt = i;
}
}
return rt;
}Analysis summary
The following issues have been detected: wrong answers.
For example, for the input [10000, -10000] the solution returned a wrong answer (got 10000 expected 0).
Analysis
expand all
Correctness tests
1.
0.068 s
OK
2.
0.068 s
WRONG ANSWER,
got 10000 expected 0
3.
0.068 s
WRONG ANSWER,
got 10000 expected 0
4.
0.068 s
OK
1.
0.068 s
OK
2.
0.068 s
WRONG ANSWER,
got 6 expected 5
1.
0.068 s
WRONG ANSWER,
got 0 expected 2
1.
0.072 s
WRONG ANSWER,
got 98 expected 17
medium_range
increasing, decreasing (legth = ~100) and small functional
increasing, decreasing (legth = ~100) and small functional
✘
WRONG ANSWER
got 9 expected 3
got 9 expected 3
1.
0.068 s
OK
2.
0.068 s
OK
3.
0.068 s
WRONG ANSWER,
got 9 expected 3
expand all
Performance tests
1.
0.072 s
WRONG ANSWER,
got 689 expected 90
1.
0.160 s
WRONG ANSWER,
got 99988 expected 0
2.
0.136 s
WRONG ANSWER,
got 80005 expected 40002
1.
0.164 s
WRONG ANSWER,
got 99996 expected 46034
1.
0.160 s
WRONG ANSWER,
got 10000 expected 0
2.
0.168 s
OK
3.
0.164 s
WRONG ANSWER,
got 99998 expected 50000
1.
0.156 s
WRONG ANSWER,
got 99988 expected 3
2.
0.136 s
WRONG ANSWER,
got 69991 expected 4