GCD时间复杂度： Since Fk is approximatelyΦ/√5，where中is the golden ratio(I+√⑤)/2de fined by equation (3.24),the number of recursive calls in EUCLID is O(Ig b). 如果从两个B位数a,b角度看： Therefore,if we call EUCLID on two B-bit numbers,then it performs O(B)arithmetic operations and O(B3)bit operations如果从两个β位数a，b角度看： GCD时间复杂度：