4 Values whose Sum is 0 poj-2785(四个长度为4000的数组，从每一个数组中取出一个数，使取出的四个数和为0 二分优化)

The SUM problem can be formulated as follows: given four lists A, B, C, D of integer values, compute how many quadruplet (a, b, c, d ) ∈ A x B x C x D are such that a + b + c + d = 0 . In the followin

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