容斥原理是对集合的运算。
举个例子三个集合的容斥原理: A ∪ B ∪ C = A + B + C - A ∩ B - B ∩ C - C ∩ A + A ∩ B ∩ C.
多个集合的容斥原理:
hdu 1796
How many integers can you find
Problem Description
Now you get a number N, and a M-integers set, you should find out how many integers which are small than N, that they can divided exactly by any integers in the set. For example, N=12, and M-integer set is {2,3}, so there is another set {2,3,4,6,8,9,10},
all the integers o......
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