题解 | #坐标移动#

思路

坐标系其实就是一个(x,y)的二元组。如果用python来解，这道题直接用元组就可以了。但是Java没有元组的概念，因此我们就需要构建一个元组。

接下来就是将输入按照;分隔符split成一个数组然后遍历操作就可以了。

代码

import java.util.ArrayList;
import java.util.Map;
import java.util.Scanner;
import java.util.StringJoiner;

public class Main {

    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        while (scanner.hasNext()) {
            String operations = scanner.next();
            String[] operationArr = operations.split(";");
            Tuple<Integer, Integer> tuple = Tuple.of(0, 0);
            for (String operation : operationArr) {
                // 长度为2或者3
                if (operation.length() == 2 || operation.length() == 3 && operation.charAt(0) >= 65 && operation.charAt(0) <= 90) {
                    if (isDigital(operation.substring(1))) {
                        // 开始运动
                        move(operation, tuple);
                    }
                }
            }
            System.out.println(tuple);
        }
    }

    private static boolean isDigital(String num) {
        char[] chars = num.toCharArray();
        for (char aChar : chars) {
            if (!Character.isDigit(aChar)) {
                return false;
            }
        }
        return true;
    }

    private static Tuple<Integer, Integer> move(String operation, Tuple<Integer, Integer> tuple) {
        String direction = operation.substring(0, 1);
        int step = Integer.parseInt(operation.substring(1));
        switch (direction) {
            case "A":
                tuple.l -= step;
                break;
            case "S":
                tuple.r -= step;
                break;
            case "D":
                tuple.l += step;
                break;
            case "W":
                tuple.r += step;
                break;
            default:
        }
        return tuple;
    }
}

class Tuple<L, R> {
    L l;
    R r;

    private Tuple(L l, R r) {
        this.l = l;
        this.r = r;
    }

    static <L, R> Tuple<L, R> of(L l, R r) {
        return new Tuple<>(l, r);
    }

    @Override
    public String toString() {
        return l + "," + r;
    }
}