n balls into n bins: Pr[bin-lhas≥t balls]≤ () Pr[max load≥t=Pr闩bin-ihas≥t balls] ≤mPr[bin-1has≥t balls] union bound ≤ () 31nn choose t= InIn n () 31nn/InInn Inn/Inlnn =ne3(In InIn n-InInn)inn/Ininn ne-3Inn+3(InInIn n)(In n)/InInn ≤ne-2lnn 1 mn balls into n bins: Pr[ bin-1 has t balls ] e t t Pr[ max load t] = Pr[ bin-i has t balls] nPr[ bin-1 has t balls ] union bound n e t t = n e ln ln n 3 ln n 3 ln n/ ln ln n < n ln ln n ln n 3 ln n/ ln ln n = ne3(ln ln ln nln ln n) ln n/ ln ln n ne2 ln n = 1 n ne3 ln n+3(ln ln ln n)(ln n)/ ln ln n t = 3 ln n ln ln n choose