LeetCode集合

https://leetcode.com/problems/roman-to-integer/submissions/

class Solution(object):
    
    SymbolValue = {
        "I": 1,
        "II": 2,
        "III": 3,
        "IV": 4,
        "V": 5,
        "VI": 6,
        "VII": 7,
        "VIII": 8,
        "IX": 9,
        "X": 10,
        "XX": 20,
        "XXX": 30,
        "XL": 40,
        "L": 50,
        "LX": 60,
        "LXX": 70,
        "LXXX": 80,
        "XC": 90,
        "C": 100,
        "CC": 200,
        "CCC": 300,
        "CD": 400,
        "D": 500,
        "DC": 600,
        "DCC": 700,
        "DCCC": 800,
        "CM": 900,
        "M": 1000,
        "MM": 2000,
        "MMM": 3000
    }
    
    SymbolList = [ "MMM", "MM", "M", "CM", "DCCC", "DCC", "DC", "D", "CD", "CCC", "CC", "C", "XC", "LXXX", "LXX", "LX", "L", "XL", "XXX", "XX", "X", "IX", "VIII", "VII", "VI", "V", "IV", "III", "II", "I"]
    
    def romanToInt(self, s):
        """
        :type s: str
        :rtype: int
        """
        res = 0
        idx = 0
        terminal = len(s)
        while idx < terminal:
            
            offset = 0
            for symbol in self.SymbolList:
                _len_symbol = len(symbol)
                if symbol == s[idx:idx + _len_symbol]:
                    offset = _len_symbol
                    res = res + self.SymbolValue[symbol]
                    break
            
            idx += offset
        
        return res
        
        
        
        

https://leetcode.com/problems/longest-common-prefix/submissions/

class Solution(object):
    def longestCommonPrefix(self, strs):
        """
        :type strs: List[str]
        :rtype: str
        """
        
        if len(strs)  == 1:
            return strs[0]
        
        prefix = strs[0]
        _len_prefix = len(prefix)
        
        Res = ""
        
        for i in range(_len_prefix, 0 , -1):
            
            Temp = prefix[0:i]
            flag = True
            for j in range(1, len(strs), 1):
                TempStrs = strs[j][0:i]
                if Temp != TempStrs:
                    flag = False
                    break
            
            
            if flag is True:
                Res = Temp
                break
        
        return Res
            
        
        

https://leetcode.com/problems/valid-parentheses/submissions/

class Solution(object):
    def isValid(self, s):
        """
        :type s: str
        :rtype: bool
        """
        stack = []
        for c in s:
            
            if len(stack) == 0:
                stack.append(c)
                continue
                
            top = stack.pop()
            
            
            if c == ")" or c == "]" or c == "}":
                temp = "%c%c"%(top, c)
                if temp == "()" or temp == "[]" or temp == "{}":
                    pass
                else:
                    stack.append(top)
                    stack.append(c)
            else:
                stack.append(top)
                stack.append(c)
        
        if len(stack) > 0:
            return False
        else:
            return True