B. The Number of Products
combinatorics; dp; implementation
You are given a sequence \(a_1, a_2, \dots, a_n\) consisting of \(n\) non-zero integers (i.e. \(a_i \ne 0\)). You have to calculate two following values: the number of pairs of indices \((l, r)\) \((l \le r)\) such that \(a_l \cdot a_{l + 1} \dots a_{r - 1} \cdot a_r\) is negative; the number of pairs of indices \((l, r)\) \((l \le r)\) such that \(a_l \cdot a_{l + 1} \dots a_{r - 1} \cdot a_r\) is positive;
The first line contains one integer \(n\) \((1 \le n \le 2 \cdot 10^{5})\) — the number of elements in the sequence.The second line contains \(n\) integers \(a_1, a_2, \dots, a_n\) \((-10^{9} \le a_i \le 10^{9}; a_i \neq 0)\) — the elements of the sequence.
Print two integers — the number of subsegments with negative product and the number of subsegments with positive product, respectively.