class Solution(object):
def minWindow(self, s, t):
"""
:type s: str
:type t: str
:rtype: str
"""
need, missing = collections.Counter(t), len(t)
i = I = J =
0
for j, c
in enumerate(s,
1):
missing -= need[c] >
0
need[c] -=
1
if not missing:
while i < j
and need[s[i]] <
0:
need[s[i]] +=
1
i +=
1
if not J
or j - i <= J - I:
I, J = i, j
return s[I:J]
