Problem5192-- Tape Equilibrium

5192: Tape Equilibrium

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Time Limit : 1.000 sec  Memory Limit : 256 MiB

Description

Minimize the value |(A[0] + ... + A[P-1]) - (A[P] + ... + A[N-1])|.
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] = 3 We 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
the answer 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].

Input

Two lines.
First line: N
Second line: N elements.

Output

One element. the minimal difference that can be achieved.

Sample 1 Input

5
3 1 2 4 3

Sample 1 Output

1

Source/Category

基础算法 4.2.前缀和