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Minimum Window Substring

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Description

https://leetcode.com/problems/minimum-window-substring/description/

Solution

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class Solution:
    def Valid(self, dic):
        for item in dic.values():
            if item > 0:
                return False
        
        return True
        
        
    
    def minWindow(self, s, t):
        """
        :type s: str
        :type t: str
        :rtype: str
        """
        
        counter_t = {}
        for ch in t:
            if not counter_t.get(ch):
                counter_t[ch] = 1
            else:
                counter_t[ch] += 1
        counter_s = {}
        for index in range(len(s)):
            if not counter_s.get(s[index]):
                counter_s[s[index]] = [[index], 0]
            else:
                counter_s[s[index]][0].append(index)
        
        start = 0
        while start < len(s):
            if counter_t.get(s[start]) is None:
                start += 1
                continue
            if counter_t.get(s[start]) >= 0:
                break
            counter_t[s[start]] -= 1
            start += 1
        print(counter_t)
                
                
        end = start 
        while end < len(s):
            if counter_t.get(s[end]) is not None:
                counter_t[ s[end] ] -= 1
                
            if not self.Valid(counter_t):
                end += 1
            else:
                break
        
        if not self.Valid(counter_t):
            return ""
        minum_start = start
        minum_end = end
        minum = end - start
        
        while start <= end:
            while start <= end:
                if counter_t.get(s[start]) is None:
                    start += 1
                    continue
                    
                if counter_t.get(s[start]) >= 0:
                    break
                    
                counter_t[ s[start] ] += 1
                start += 1
            if end - start < minum:
                minum_start = start
                minum_end = end
                minum = end - start
                print(start, end, counter_t)
            
            result_list = counter_s.get(s[start])
            next_end = None
            for index in range(result_list[1], len(result_list[0])):
                if result_list[0][index] > end:
                    next_end = result_list[0][index]
                    result_list[1] = index + 1
                    break
            
            if next_end is None:
                break
            
            for index in range(end + 1, next_end + 1):
                if counter_t.get(s[index]) is not None:
                    counter_t[s[index]] -= 1      
            end = next_end
            
        return s[minum_start: minum_end + 1]