_1496.java

package com.fishercoder.solutions;

import java.util.Objects;
import java.util.Stack;

public class _1496 {
    public static class Solution1 {
        public boolean isPathCrossing(String path) {
            Stack<Coord> visited = new Stack<>();
            visited.add(new Coord(0, 0));
            for (char c : path.toCharArray()) {
                Coord last = visited.peek();
                if (c == 'N') {
                    Coord nextStep = new Coord(last.x, last.y + 1);
                    if (visited.contains(nextStep)) {
                        return true;
                    }
                    visited.add(nextStep);
                } else if (c == 'S') {
                    Coord nextStep = new Coord(last.x, last.y - 1);
                    if (visited.contains(nextStep)) {
                        return true;
                    }
                    visited.add(nextStep);
                } else if (c == 'E') {
                    Coord nextStep = new Coord(last.x - 1, last.y);
                    if (visited.contains(nextStep)) {
                        return true;
                    }
                    visited.add(nextStep);
                } else if (c == 'W') {
                    Coord nextStep = new Coord(last.x + 1, last.y);
                    if (visited.contains(nextStep)) {
                        return true;
                    }
                    visited.add(nextStep);
                }
            }
            return false;
        }

        static class Coord {
            int x;
            int y;

            public Coord(int x, int y) {
                this.x = x;
                this.y = y;
            }

            @Override
            public boolean equals(Object o) {
                if (this == o) {
                    return true;
                }
                if (o == null || getClass() != o.getClass()) {
                    return false;
                }
                Coord coord = (Coord) o;
                return x == coord.x && y == coord.y;
            }

            @Override
            public int hashCode() {
                return Objects.hash(x, y);
            }
        }
    }
}