[Leetcode从零开刷]657. Judge Route Circle

题目来源：
leetcode:
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

翻译：
假设有个机器人在（0，0）的位置，判断这个机器人在移动过后是否能够返回到原点。
移动顺序是由一个字符串给出的，假设R代表右移一步，L代表做移一步，以此类推，UD等。

举例：
输入“UD”，则能回去，输出“TRUE”
输入”LL”，则一直往左边走，输出”False”

cpp:

class Solution {public:    bool judgeCircle(string moves) {     //moves其实就是个字符串，检测UDRL的个数，UD相反，则可以回到原点，RL类似        int v = 0;        int h = 0;        for (char ch : moves) {            switch (ch) {                case 'U' : v++; break;                case 'D' : v--; break;                case 'R' : h++; break;                case 'L' : h--; break;            }        }        return v == 0 && h == 0;         }};

java:

public class Solution {    public boolean judgeCircle(String moves) {        int x = 0;        int y = 0;        for (char ch : moves.toCharArray()) {            if (ch == 'U') y++;            else if (ch == 'D') y--;            else if (ch == 'R') x++;            else if (ch == 'L') x--;        }        return x == 0 && y == 0;    }}