Tasks Details
easy
Minimize the value |(A[0] + ... + A[P-1]) - (A[P] + ... + A[N-1])|.
Task Score
66%
Correctness
100%
Performance
33%
A non-empty array A consisting of N integers is given. Array A represents numbers on a tape.
Any integer P, such that 0 < P < N, splits this tape into two non-empty parts: A[0], A[1], ..., A[P − 1] and A[P], A[P + 1], ..., A[N − 1].
The difference between the two parts is the value of: |(A[0] + A[1] + ... + A[P − 1]) − (A[P] + A[P + 1] + ... + A[N − 1])|
In other words, it is the absolute difference between the sum of the first part and the sum of the second part.
For example, consider array A such that:
A[0] = 3 A[1] = 1 A[2] = 2 A[3] = 4 A[4] = 3We can split this tape in four places:
- P = 1, difference = |3 − 10| = 7
- P = 2, difference = |4 − 9| = 5
- P = 3, difference = |6 − 7| = 1
- P = 4, difference = |10 − 3| = 7
Write a function:
class Solution { public int solution(int[] A); }
that, given a non-empty array A of N integers, returns the minimal difference that can be achieved.
For example, given:
A[0] = 3 A[1] = 1 A[2] = 2 A[3] = 4 A[4] = 3the 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 [−1,000..1,000].
Copyright 2009–2024 by Codility Limited. All Rights Reserved. Unauthorized copying, publication or disclosure prohibited.
Solution
Programming language used C#
Time spent on task 2 minutes
Notes
not defined yet
Task timeline
Code: 09:42:40 UTC,
cpp,
verify,
result: Failed
using System;
// you can also use other imports, for example:
// using System.Collections.Generic;
// you can write to stdout for debugging purposes, e.g.
// Console.WriteLine("this is a debug message");
class Solution {
public int solution(int[] A) {
// write your code in C# 6.0 with .NET 4.5 (Mono)
int[] arr_first, arr_second;
int min_difference = Int32.MaxValue;
for (int P = 1; P < A.Length; P++)
{
int sum_first = 0;
for (int i = 0; i < P; i++)
{
sum_first += A[i];
}
int sum_second = 0;
for (int i = P; i < A.Length; i++)
{
sum_second += A[i];
}
int difference = Math.Abs(sum_first - sum_second);
if (difference < min_difference)
{
min_difference = difference;
}
}
return min_difference;
}
}
Analysis
Compile error
func.cpp:1:7: error: expected nested-name-specifier before 'System'
using System;
^
func.cpp:1:7: error: 'System' has not been declared
func.cpp:9:12: error: expected ':' before 'int'
public int solution(int[] A) {
^
func.cpp:9:31: error: expected ',' or '...' before 'A'
public int solution(int[] A) {
^
func.cpp:36:1: error: expected ';' after class definition
}
^
func.cpp: In member function 'int Solution::solution(int*)':
func.cpp:11:12: error: expected unqualified-id before '[' token
int[] arr_first, arr_second;
^
func.cpp:12:30: error: 'Int32' was not declared in this scope
int min_difference = Int32.MaxValue;
^
func.cpp:13:29: error: 'A' was not declared in this scope
for (int P = 1; P < A.Length; P++)
^
func.cpp:27:30: error: 'Math' was not declared in this scope
int difference = Math.Abs(sum_first - sum_second);
^
Code: 09:43:03 UTC,
cs,
verify,
result: Passed
using System;
// you can also use other imports, for example:
// using System.Collections.Generic;
// you can write to stdout for debugging purposes, e.g.
// Console.WriteLine("this is a debug message");
class Solution {
public int solution(int[] A) {
// write your code in C# 6.0 with .NET 4.5 (Mono)
int[] arr_first, arr_second;
int min_difference = Int32.MaxValue;
for (int P = 1; P < A.Length; P++)
{
int sum_first = 0;
for (int i = 0; i < P; i++)
{
sum_first += A[i];
}
int sum_second = 0;
for (int i = P; i < A.Length; i++)
{
sum_second += A[i];
}
int difference = Math.Abs(sum_first - sum_second);
if (difference < min_difference)
{
min_difference = difference;
}
}
return min_difference;
}
}
User test case 1:
[-1000, 1000]
Analysis
Code: 09:43:13 UTC,
cs,
verify,
result: Passed
using System;
// you can also use other imports, for example:
// using System.Collections.Generic;
// you can write to stdout for debugging purposes, e.g.
// Console.WriteLine("this is a debug message");
class Solution {
public int solution(int[] A) {
// write your code in C# 6.0 with .NET 4.5 (Mono)
int[] arr_first, arr_second;
int min_difference = Int32.MaxValue;
for (int P = 1; P <= A.Length; P++)
{
int sum_first = 0;
for (int i = 0; i < P; i++)
{
sum_first += A[i];
}
int sum_second = 0;
for (int i = P; i < A.Length; i++)
{
sum_second += A[i];
}
int difference = Math.Abs(sum_first - sum_second);
if (difference < min_difference)
{
min_difference = difference;
}
}
return min_difference;
}
}
User test case 1:
[-1000, 1000]
Analysis
Code: 09:43:22 UTC,
cs,
verify,
result: Passed
using System;
// you can also use other imports, for example:
// using System.Collections.Generic;
// you can write to stdout for debugging purposes, e.g.
// Console.WriteLine("this is a debug message");
class Solution {
public int solution(int[] A) {
// write your code in C# 6.0 with .NET 4.5 (Mono)
int[] arr_first, arr_second;
int min_difference = Int32.MaxValue;
for (int P = 1; P < A.Length; P++)
{
int sum_first = 0;
for (int i = 0; i < P; i++)
{
sum_first += A[i];
}
int sum_second = 0;
for (int i = P; i < A.Length; i++)
{
sum_second += A[i];
}
int difference = Math.Abs(sum_first - sum_second);
if (difference < min_difference)
{
min_difference = difference;
}
}
return min_difference;
}
}
User test case 1:
[-1000, 1000]
Analysis
Code: 09:43:27 UTC,
cs,
verify,
result: Passed
using System;
// you can also use other imports, for example:
// using System.Collections.Generic;
// you can write to stdout for debugging purposes, e.g.
// Console.WriteLine("this is a debug message");
class Solution {
public int solution(int[] A) {
// write your code in C# 6.0 with .NET 4.5 (Mono)
int[] arr_first, arr_second;
int min_difference = Int32.MaxValue;
for (int P = 1; P < A.Length; P++)
{
int sum_first = 0;
for (int i = 0; i < P; i++)
{
sum_first += A[i];
}
int sum_second = 0;
for (int i = P; i < A.Length; i++)
{
sum_second += A[i];
}
int difference = Math.Abs(sum_first - sum_second);
if (difference < min_difference)
{
min_difference = difference;
}
}
return min_difference;
}
}
User test case 1:
[-1000, 1000]
Analysis
Code: 09:43:32 UTC,
cs,
final,
score:
66
using System;
// you can also use other imports, for example:
// using System.Collections.Generic;
// you can write to stdout for debugging purposes, e.g.
// Console.WriteLine("this is a debug message");
class Solution {
public int solution(int[] A) {
// write your code in C# 6.0 with .NET 4.5 (Mono)
int[] arr_first, arr_second;
int min_difference = Int32.MaxValue;
for (int P = 1; P < A.Length; P++)
{
int sum_first = 0;
for (int i = 0; i < P; i++)
{
sum_first += A[i];
}
int sum_second = 0;
for (int i = P; i < A.Length; i++)
{
sum_second += A[i];
}
int difference = Math.Abs(sum_first - sum_second);
if (difference < min_difference)
{
min_difference = difference;
}
}
return min_difference;
}
}Analysis summary
The following issues have been detected: timeout errors.
Analysis
Detected time complexity:
O(N * N)
expand all
Correctness tests
1.
0.059 s
OK
2.
0.060 s
OK
1.
0.060 s
OK
1.
0.060 s
OK
1.
0.060 s
OK
1.
0.061 s
OK
1.
0.059 s
OK
expand all
Performance tests
1.
0.153 s
OK
1.
0.152 s
OK
large_ones
large sequence, numbers from -1 to 1, length = ~100,000
large sequence, numbers from -1 to 1, length = ~100,000
✘
TIMEOUT ERROR
running time: >6.00 sec., time limit: 0.34 sec.
running time: >6.00 sec., time limit: 0.34 sec.
1.
6.000 s
TIMEOUT ERROR,
running time: >6.00 sec., time limit: 0.34 sec.
2.
6.000 s
TIMEOUT ERROR,
running time: >6.00 sec., time limit: 0.34 sec.
large_random
random large, length = ~100,000
random large, length = ~100,000
✘
TIMEOUT ERROR
running time: >6.00 sec., time limit: 0.37 sec.
running time: >6.00 sec., time limit: 0.37 sec.
1.
6.000 s
TIMEOUT ERROR,
running time: >6.00 sec., time limit: 0.37 sec.
2.
6.000 s
TIMEOUT ERROR,
running time: >6.00 sec., time limit: 0.37 sec.
large_sequence
large sequence, length = ~100,000
large sequence, length = ~100,000
✘
TIMEOUT ERROR
running time: 2.30 sec., time limit: 0.33 sec.
running time: 2.30 sec., time limit: 0.33 sec.
1.
2.300 s
TIMEOUT ERROR,
running time: 2.30 sec., time limit: 0.33 sec.
large_extreme
large test with maximal and minimal values, length = ~100,000
large test with maximal and minimal values, length = ~100,000
✘
TIMEOUT ERROR
running time: >6.00 sec., time limit: 0.37 sec.
running time: >6.00 sec., time limit: 0.37 sec.
1.
6.000 s
TIMEOUT ERROR,
running time: >6.00 sec., time limit: 0.37 sec.
2.
6.000 s
TIMEOUT ERROR,
running time: >6.00 sec., time limit: 0.38 sec.
3.
5.786 s
TIMEOUT ERROR,
running time: 5.79 sec., time limit: 0.35 sec.