1 class Solution: 2 def minWindow(self, s: str, t: str) -> str: 3 n = len(s) 4 if n==0: 5 return "" 6 if len(t)==0: 7 return s 8 #if s == t: 9 # return s 10 dic = {} 11 dic2= {} 12 for i in range(len(t)): 13 dic.update({t[i]:0}) 14 if t[i] in dic2.keys(): 15 dic2.update({t[i]:dic2[t[i]]+1}) 16 else: 17 dic2.update({t[i]:1}) 18 #dicount = len(t) 19 i = 0 20 j = 0 21 minstr = "" 22 minwidth = n 23 while i <=j and j<n : 24 #j++ 25 if s[j] in t: 26 dic.update({s[j]:dic[s[j]]+1}) 27 valid = True 28 for k in dic.keys(): 29 if dic[k]<dic2[k]: 30 valid = False 31 break 32 if valid: 33 #valid 34 curlen = j-i+1 35 if curlen<=min 36 minwidth = curlen 37 minstr = s[i:j+1] 38 #i++ 39 while i<=j: 40 if s[i] not in dic.keys(): 41 i += 1 42 else: 43 if dic[s[i]]>dic2[s[i]]: 44 dic.update({s[i]:dic[s[i]]-1}) 45 i += 1 46 else: 47 curlen = j-i+1 48 if curlen <= min 49 minwidth = curlen 50 minstr = s[i:j+1] 51 break 52 #else: 53 #invalid 54 55 j += 1 56 57 return minstr