折半查找（二分查找）

#coding:utf-8


'''
折半查找返回值是mid+1
'''

def half_search(data,target):
    low,high = 0,len(data)-1
    while low<=high:
        mid = (low+high)//2
        if data[mid] == target:
            return  mid+1
        elif data[mid] > target:
            high = mid -1
        else:
         low = mid+1
    return 0




data = [1,3,4,67,6]
target = 6
a=half_search(data,target)-1
print a