LeetCode刷题：657. Judge Route Circle
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
算法设计
package com.bean.basic;public class JudgeRouteCircle {public static boolean judgeCircle(String moves) {//设定两个变量x，y；分别表示平面图形的横坐标和纵坐标int x = 0;int y = 0;//将字符串转化为字符数组后，进行迭代for (char ch : moves.toCharArray()) {/** 向上移动的方向，纵坐标 y--* 向下移动的方向，纵坐标 y++* 向左移动的方向，横坐标 x--* 向右移动的方向，横坐标 x++*/if (ch == 'U') y++;else if (ch == 'D') y--;else if (ch == 'R') x++;else if (ch == 'L') x--;}// 路径形成一个环路的条件是：x==0 && y==0return x == 0 && y == 0;}public static void main(String[] args) {// TODO Auto-generated method stub//String str="UD";String str="LL";if(judgeCircle(str)) {System.out.println("True");}else {System.out.println("False");}}}
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