※ 引述《MLPfim (rewhblye)》之銘言：
: 如題，朋友傳給我的，出自102板中
: https://i.imgur.com/cvfLCzQ.jpg
: 從第一行我就看不懂了，請問有高手可以解釋一下這題的解法嗎？
f(x) = a_0 + a_1w + a_2x^2 + ... + a_200x^200 = (1 + x + x^2)^100
f(1) = a_0 + a_1 + ... + a_198 = 3^100
f(w) = [a_0 + a_3 + ... + a_198] + w[a_1 + a_4 + ... + a_199]
+ w^2 [a_2 + a_5 + ... + a_200]
= A + Bw + Cw^2 = 0
f(w^2) = A + Bw^2 + Cw = 0
所以f(1) = A + B + C = 3^100
又f(w) = A + Bw + C(-1 - w) = (A - C) + (B - C)w
f(w^2) = A + B(-w - 1) + Cw = (A - B) + (C - B)w
=> B = C = A
=> A = B = C = 3^99
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