LeetCode：657. Judge Route Circle

链接：
https://leetcode.com/problems/judge-route-circle/description/

题目：
Initially, there is a Robot at position (0, 0). Given a sequence of its moves, judge if this robot makes a circle, which means it moves back to the original place.

The move sequence is represented by a string. And each move is represent by a character. The valid robot moves are R (Right), L (Left), U (Up) and D (down). The output should be true or false representing whether the robot makes a circle.

Example 1:
Input: “UD”
Output: true
Example 2:
Input: “LL”
Output: false

思路：
dict或者elif

Answer：
dict

class Solution:
    def judgeCircle(self, moves):
        """
        :type moves: str
        :rtype: bool
        """
        table = {
            'R': 1,
            'L': -1,
            'U': 1.5,
            'D': -1.5
        }
        sum = 0
        for move in moves:
            sum += table[move]
        return sum==0

elif

class Solution(object):
    def judgeCircle(self, moves):
        x = y = 0
        for move in moves:
            if move == 'U': y -= 1
            elif move == 'D': y += 1
            elif move == 'L': x -= 1
            elif move == 'R': x += 1

        return x == y == 0