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].
using System;
// you can also use other imports, for example:
// using System.Collections.Generic;
// you can use Console.WriteLine for debugging purposes, e.g.
// Console.WriteLine("this is a debug message");
class Solution {
public int solution(int[] A) {
// No solution exists for...
if (A == null) return -1;
// Hold sums below the fold...
long lower = 0;
long upper = 0;
var min = long.MaxValue;
// Sum All to get "Upper"
for (long i = 0; i < A.Length; i++) upper += A[i];
// foreach in array...
// ... Shift number from upper to lower a
// ... Calculate new difference
foreach (var i in A)
{
lower += i;
upper -= i;
var diff = Math.Abs(upper - lower);
min = Math.Min(min, diff);
if (diff == 0) return 0;
}
return (int) min;
}
}
using System;
// you can also use other imports, for example:
// using System.Collections.Generic;
// you can use Console.WriteLine for debugging purposes, e.g.
// Console.WriteLine("this is a debug message");
class Solution {
public int solution(int[] A) {
// No solution exists for...
if (A == null) return -1;
if (A.Length == 0) return -1;
if (A.Length == 1) return -1;
if (A.Length == 2) return Math.Abs(A[0]-A[1]);
// Hold sums below the fold...
long lower = 0;
long upper = 0;
var min = long.MaxValue;
// Sum All to get "Upper"
for (long i = 0; i < A.Length; i++) upper += A[i];
// foreach in array...
// ... Shift number from upper to lower a
// ... Calculate new difference
foreach (var i in A)
{
lower += i;
upper -= i;
var diff = Math.Abs(upper - lower);
min = Math.Min(min, diff);
if (diff == 0) return 0;
}
return (int) min;
}
}
using System;
// you can also use other imports, for example:
// using System.Collections.Generic;
// you can use Console.WriteLine for debugging purposes, e.g.
// Console.WriteLine("this is a debug message");
class Solution {
public int solution(int[] A) {
// No solution exists for...
if (A == null) return -1;
if (A.Length == 0) return -1;
if (A.Length == 1) return -1;
if (A.Length == 2) return Math.Abs(A[0]-A[1]);
// Hold sums below the fold...
long lower = 0;
long upper = 0;
var min = long.MaxValue;
// Sum All to get "Upper"
for (long i = 0; i < A.Length; i++) upper += A[i];
// foreach in array...
// ... Shift number from upper to lower a
// ... Calculate new difference
foreach (var i in A)
{
lower += i;
upper -= i;
var diff = Math.Abs(upper - lower);
min = Math.Min(min, diff);
if (diff == 0) return 0;
}
return (int) min;
}
}
using System;
// you can also use other imports, for example:
// using System.Collections.Generic;
// you can use Console.WriteLine for debugging purposes, e.g.
// Console.WriteLine("this is a debug message");
class Solution {
public int solution(int[] A) {
// No solution exists for...
if (A == null) return -1;
if (A.Length == 0) return -1;
if (A.Length == 1) return -1;
if (A.Length == 2) return Math.Abs(A[0]-A[1]);
// Hold sums below the fold...
long lower = 0;
long upper = 0;
var min = long.MaxValue;
// Sum All to get "Upper"
for (long i = 0; i < A.Length; i++) upper += A[i];
// foreach in array...
// ... Shift number from upper to lower a
// ... Calculate new difference
foreach (var i in A)
{
lower += i;
upper -= i;
var diff = Math.Abs(upper - lower);
min = Math.Min(min, diff);
if (diff == 0) return 0;
}
return (int) min;
}
}
The following issues have been detected: wrong answers.