【Leecode刷题】字典使用&杨辉三角

【Leecode刷题】字典使用&杨辉三角

本题的重点是：

 map_ = {}
 morse = [".-","-...","-.-.","-..",".","..-.","--.","....","..",".---","-.-",".-..","--","-.","---",".--.","--.-",".-.","...","-","..-","...-",".--","-..-","-.--","--.."]
 asc = 97
 for i in range(26):
     map_[chr(asc+i)] = morse[i]
# set把列表转换成集合
map_morse = set(map_morse)

class Solution(object):
    def uniqueMorseRepresentations(self, words):
        """
        :type words: List[str]
        :rtype: int
        """
        map_ = {}
        morse = [".-","-...","-.-.","-..",".","..-.","--.","....","..",".---","-.-",".-..","--","-.","---",".--.","--.-",".-.","...","-","..-","...-",".--","-..-","-.--","--.."]
        asc = 97
        for i in range(26):
            map_[chr(asc+i)] = morse[i]
        map_morse = []
        for word in words:
            temp = ""
            for alpha in word:
                temp += map_[alpha]
            map_morse.append(temp)
        map_morse = set(map_morse)
        return len(map_morse)

杨辉三角第 n n n行第 i i i个数据 ( 1 ≤ i ≤ n ) (1 \leq i \leq n) (1≤i≤n)数据是 C n i C_n^i Cni​

class Solution(object):
    def getRow(self, rowIndex):
        """
        :type rowIndex: int
        :rtype: List[int]
        """
        def mutiple(m):
            num=1
            for i in range(m):
                num=num*(i+1)
            return num
        def zuheshu(m,n):
            return mutiple(m)/(mutiple(n)*mutiple(m-n))
        a=[]
        for i in range(rowIndex+1):
            a.append(zuheshu(rowIndex,i))
        return a