LeetCode刷题笔记（一）

771. Jewels and Stones：
You're given strings J representing the types of stones that are jewels, and S representing the stones you have.  Each character in S is a type of stone you have.  You want to know how many of the stones you have are also jewels.

The letters in J are guaranteed distinct, and all characters in J and S are letters. Letters are case sensitive, so "a" is considered a different type of stone from "A".
题目挺简单的，大概意思是：键盘输入字符串J,S;若S字符串中含有的字母J字符串也有，J中的字母被视为宝石，S中部和J中字母相同的字母被定义为石头；

错误代码：

class Solution:
    def numJewelsInStones(self, J, S):
        """
        :type J: str
        :type S: str
        :rtype: int
        """
        
        count = 0
        for s in S:
            if s in J:
                count += 1
        return count

J = input("请输入字符串：")
S = input("请输入字符串:")
s1 = Solution()
res = s1.numJewelsInStones(J, S)
print(res)

 

正确代码：

class Solution:
    def numJewelsInStones(self, J, S):
        """
        :type J: str
        :type S: str
        :rtype: int
        """
        
        count = 0
        for s in S:
            if s in J:
                count += 1
        return count


# J = "aA"
# S = "aAAbbbb"
# s1 = Solution()
# res = s1.numJewelsInStones(J, S)
# print(res)

在LeetCode上提交代码时不用自己创建对象，也不用自己调用，还有一种方法：

class Solution:
    def numJewelsInStones(self, J, S):
        """
        :type J: str
        :type S: str
        :rtype: int
        """
        count = 0
        for s in S:
            for j in J:
                if s==j:
                    count += 1
        return count