leetcode——65. 有效数字

我太难了，俩小时。。。。。。

class Solution(object):
    def isNumber(self, s):
        """
        :type s: str
        :rtype: bool
        """
        s=s.strip()
        for i in range(len(s)):
            if s[i] not in ‘e0123456789+-.‘:
                return False
        if len(s)<1:
            return False
        if len(s)==1:
            if s[0] not in ‘0123456789‘:
                return False
        if s[0] in ‘e‘ or s[-1] in ‘e+-‘:
            return False
        if s.count(‘e‘)>1:
            return False
        if s.count(‘e‘)==1:
            if s.count(‘.‘)>1:
                return False
            elif s.count(‘.‘)==1:
                #print(‘gygufyufu‘)
                if s[0]==‘.‘ and s[1]==‘e‘:
                    return False
                if s.index(‘e‘)==s.index(‘.‘)-1:
                    return False
                if s.index(‘.‘)>s.index(‘e‘):
                    return False
                if s.index(‘.‘)<s.index(‘e‘):
                    if s[s.index(‘.‘)+1] in ‘+-‘:
                        return False        
                if s[-1]!=‘.‘:
                    return True
                else:
                    return False
                if s.count(‘+‘)+s.count(‘-‘)>2:
                    return False
                elif s.count(‘+‘)+s.count(‘-‘)==2:
                    if s[0] in ‘+-‘ and s[s.index(‘e‘)+1] in ‘+-‘:
                        return True
                    else:
                        return False
                
                elif s.count(‘+‘)+s.count(‘-‘)==1:
                    if s[0] in ‘+-‘ or s[s.index(‘e‘)+1] in ‘+-‘:
                        return True    
                    else:
                        return False
            else:
                if s.count(‘+‘)+s.count(‘-‘)>2:
                    return False
                elif s.count(‘+‘)+s.count(‘-‘)==2:
                    if s[0] in ‘+-‘ and s[s.index(‘e‘)+1] in ‘+-‘:
                        return True
                    else:
                        return False
                elif s.count(‘+‘)+s.count(‘-‘)==1:
                    if s[0] in ‘+-‘ :
                        if s[1]==‘e‘:
                            return False
                        else:
                            return True    
                    elif s[s.index(‘e‘)+1] in ‘+-‘ and len(s)>s.index(‘e‘)+2:
                        return True
                    else:
                        return False
        else:
            if s.count(‘.‘)>1:
                return False
            elif s.count(‘.‘)==1:
                if s.count(‘+‘)+s.count(‘-‘)>1:
                    return False
                elif s.count(‘+‘)+s.count(‘-‘)==1:
                    if s[0] in ‘+-‘ :
                        if len(s)==2:
                            if s[1]==‘.‘:
                                return False
                            else:
                                return True
                        elif len(s)>2:
                            if s[1]==‘.‘ and s[2] not in ‘0123456789‘:
                                return False
                            else:
                                return True
                        else:
                            return True    
                    else:
                        return False
                if s[s.index(‘.‘)-1] in ‘+-‘:
                    return False
            else:
                if s.count(‘+‘)+s.count(‘-‘)>1:
                    return False
                elif s.count(‘+‘)+s.count(‘-‘)==1:
                    if s[0] in ‘+-‘:
                        return True    
                    else:
                        return False
        return True

执行用时为 12 ms 的范例
class Solution(object):
    def isNumber(self, s):
        """
        :type s: str
        :rtype: bool
        """
        if not s:
            return False
            
        s = s.strip()
        sci = s.split(‘e‘)
        if len(sci) > 2:
            return False
        if len(sci) == 1:
            return False if not sci[0] else self.is_num(s)
            
        signs = [‘-‘, ‘+‘]
        sci[1] = sci[1] if not sci[1] or sci[1][0] not in signs else sci[1][1:]
        
        return self.is_num(sci[0]) and self.is_int(sci[1])
        
    def is_num(self, s):
        if not s:
            return False
            
        signs = [‘-‘, ‘+‘]
            
        parts = s.split(‘.‘)
        if len(parts) > 2:
            return False
        
        parts[0] = parts[0] if not parts[0] or parts[0][0] not in signs else parts[0][1:]
        if len(parts) == 1:
            return self.is_int(parts[0])
            
        if not parts[0] and self.is_int(parts[1]):
            return True
        
        if not parts[1] and self.is_int(parts[0]):
            return True
            
        return self.is_int(parts[0]) and self.is_int(parts[1])
        
    def is_int(self, s):
        if not s:
            return False 
            
        for i in range(0, len(s)):
            if not s[i].isdigit():
                return False
                
        return True

没仔细看。。。

                                                                                       ——2019.10.11