55. 伪代码Closest-Pair(P, l, r)
if r – l < 3 then return Brute-Force(P, l, r)
q ¬ é(l+r)/2ù
dl ¬ Closest-Pair(P, l, q-1)
dr ¬ Closest-Pair(P, q, r)
d ¬ min(dl, dr)
for i ¬ l to r do
if P[q].x - d £ P[i].x £ P[q].x + d then
append P[i] to S
Sort S on y-coordinate
for j ¬ 1 to size_of(S)-1 do
if any of d(S[j],S[j]+1), ..., d(S[j],S[j]+7) is smaller than d, set d to the smallest
return d
