BZOJ #3853. GCD Array

给你一个序列,支持两个操做:html n , d , v , a [ i ] + = [ ( i , n ) = d ] ∗ v n,d,v,a[i]+=[(i,n)=d]*v n,d,v,a[i]+=[(i,n)=d]∗v 求a的前缀和. a [ i ] + = [ ( i , n ) = d ] ∗ v = [ ( i / d , n / d ) = 1 ] ∗ v = ∑ k ∣ ( i /

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