Найти количество способов поставить числа 1 и - 1 в строку длиной 2n так, чтобы сумма строки было нулевой, а сумма любого начального отрезка было неотрицательной.
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Spectral::Cup 2026 Round 1 (Codeforces Round 1094, Div. 1 + Div. 2)
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Do you mean problem 3.6 from our homework?
Ahper Hay es???
Hay em, Axper.