def bin_search(items, key): |
"""折半查找""" |
start, end = 0 , len (items) - 1 |
while start < = end: |
mid = (start + end) / / 2 |
if key > items[mid]: |
start = mid + 1 |
elif key < items[mid]: |
end = mid - 1 |
else : |
return mid |
return - 1 |