二分查找

#-*- coding:utf-8-*-
#查找列表中的一个元素，列表是排好序的；

#普通方法说
def search(list,element):
    for i in range(0,len(list)):
        if list[i] == element:
            print("list[%d] is %d" % (i,element))
            return i
    print "not found!"

#二分法查找，要求列表是有序的才行
def search2(list,element):
    low = 0
    high = len(list)-1
    while low <= high:
        middle = (low+high)/2
        if list[middle]>element:
            high = middle-1
        elif list[middle] < element:
            low = middle+1
        else:
            print("list[%d] is %d" % (middle,element))
            return 1
    print "not found!"



if __name__ == "__main__":
    list = [1, 3, 5, 7, 8, 9, 12, 45, 68]
    element = 6
    search2(list,element)