Problems > Count Sign Changes

Count Sign Changes

Difficulty: 1100 2000 ms 128 MB

implementation

Ignoring zeros, count how many times consecutive remaining values change sign (positive to negative or vice versa).

Input: the first line has an integer N; the second line has N integers separated by spaces.

Output: one integer — the number of sign changes after removing zeros.

Constraints:

  • 1 ≤ N ≤ 2000
  • −109 ≤ ai ≤ 109

Sample Tests

Input 1
6
3 -2 0 -5 4 1
Output 1
2
Input 2
3
0 0 0
Output 2
0

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