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jakovmitrovskijakovmitrovski
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add KillingZombies solution
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‎medium300/ConnectingBrridges.java renamed to ‎medium300/ConnectingBridges.java

File renamed without changes.

‎veryhard400/KillingZombies.java

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package veryhard400;
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import java.util.*;
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public class KillingZombies {
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char turnClockwise(char c) {
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if (c == 'N')
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return 'E';
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else if (c == 'E')
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return 'S';
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else if (c == 'S')
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return 'W';
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else if (c == 'W')
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return 'N';
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return c;
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}
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class Zombie {
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int id;
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int x, y;
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char direction;
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public Zombie(int id, int x, int y, char direction) {
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this.id = id;
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this.x = x;
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this.y = y;
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this.direction = direction;
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}
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@Override
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public boolean equals(Object o) {
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if (this == o)
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return true;
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if (o == null || getClass() != o.getClass())
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return false;
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Zombie zombie = (Zombie) o;
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return x == zombie.x && y == zombie.y && direction == zombie.direction;
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}
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@Override
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public int hashCode() {
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return Objects.hash(x, y, direction);
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}
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}
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class State {
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int x, y;
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List<Zombie> zombies;
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int mask;
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public State(int x, int y, List<Zombie> zombies, int mask) {
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this.x = x;
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this.y = y;
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this.zombies = zombies;
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this.mask = mask;
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}
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@Override
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public boolean equals(Object o) {
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if (this == o)
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return true;
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if (o == null || getClass() != o.getClass())
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return false;
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State state = (State) o;
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return x == state.x && y == state.y && Objects.equals(zombies, state.zombies);
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}
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@Override
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public int hashCode() {
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return Objects.hash(x, y, zombies);
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}
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}
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Zombie moveZombie(Zombie z, int n, int m, String[] field) {
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if (z.direction == 'N') {
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if (field[z.x - 1].charAt(z.y) != '#')
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return new Zombie(z.id, z.x - 1, z.y, z.direction);
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else
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return new Zombie(z.id, z.x, z.y, turnClockwise(z.direction));
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} else if (z.direction == 'S') {
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if (field[z.x + 1].charAt(z.y) != '#')
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return new Zombie(z.id, z.x + 1, z.y, z.direction);
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else
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return new Zombie(z.id, z.x, z.y, turnClockwise(z.direction));
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} else if (z.direction == 'W') {
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if (field[z.x].charAt(z.y - 1) != '#')
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return new Zombie(z.id, z.x, z.y - 1, z.direction);
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else
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return new Zombie(z.id, z.x, z.y, turnClockwise(z.direction));
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} else if (z.direction == 'E') {
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if (field[z.x].charAt(z.y + 1) != '#')
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return new Zombie(z.id, z.x, z.y + 1, z.direction);
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else
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return new Zombie(z.id, z.x, z.y, turnClockwise(z.direction));
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}
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return new Zombie(0, 0, 0, 'x');
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}
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public int timeToKill(String[] field) {
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int n = field.length, m = field[0].length();
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int sx = 0, sy = 0;
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int cnt = 0;
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List<Zombie> zombies = new ArrayList<>();
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for (int i = 0; i < n; i++) {
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for (int j = 0; j < m; j++) {
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if (field[i].charAt(j) == 'H') {
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sx = i;
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sy = j;
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}
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if (field[i].charAt(j) == 'N' || field[i].charAt(j) == 'W' || field[i].charAt(j) == 'S'
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|| field[i].charAt(j) == 'E') {
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zombies.add(new Zombie(cnt++, i, j, field[i].charAt(j)));
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}
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}
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}
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// Map<State, Boolean> visited = new HashMap<>();
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// Map<State, Integer> dp = new HashMap<>();
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int[][][] dp = new int[21][21][1 << 12];
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for (int i = 0; i < n; i++)
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for (int j = 0; j < m; j++)
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for (int k = 0; k < 1 << cnt; k++)
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dp[i][j][k] = 1 << 25;
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Queue<State> q = new LinkedList<>();
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State start = new State(sx, sy, zombies, 0);
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dp[sx][sy][0] = 0;
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q.add(start);
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int[] dx = { -1, 1, 0, 0, 0 };
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int[] dy = { 0, 0, -1, 1, 0 };
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while (!q.isEmpty()) {
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State curr = q.remove();
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// System.out.println(curr.x + " " + curr.y + " " +
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// Integer.toBinaryString(curr.mask) + " " + " Zombies: ");
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// for (int i=0; i< curr.zombies.size(); i++)
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// System.out.println(curr.zombies.get(i).x + " " + curr.zombies.get(i).y + " "
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// + curr.zombies.get(i).direction);
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if (dp[curr.x][curr.y][curr.mask] > 100)
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continue;
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if (curr.mask == ((1 << cnt) - 1)) {
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return dp[curr.x][curr.y][curr.mask];
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}
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List<Zombie> movedZombies = new ArrayList<>();
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for (Zombie z : curr.zombies)
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movedZombies.add(moveZombie(z, n, m, field));
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for (int move = 0; move < 5; move++) {
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int nx = curr.x + dx[move], ny = curr.y + dy[move];
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if (nx >= 0 && nx < n && ny >= 0 && ny < m && field[nx].charAt(ny) != '#') {
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List<Zombie> samePos = new ArrayList<>();
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for (Zombie zombie : movedZombies) {
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if ((nx == zombie.x && ny == zombie.y))
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samePos.add(zombie);
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}
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if (dp[nx][ny][curr.mask] > dp[curr.x][curr.y][curr.mask] + 1) {
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State next = new State(nx, ny, movedZombies, curr.mask);
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dp[nx][ny][curr.mask] = dp[curr.x][curr.y][curr.mask] + 1;
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q.add(next);
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}
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if (samePos.size() > 0) {
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for (Zombie samePo : samePos) {
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List<Zombie> nextZombies = new ArrayList<>(movedZombies);
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nextZombies.remove(samePo);
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int nmask = (curr.mask | (1 << samePo.id));
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State next = new State(nx, ny, nextZombies, nmask);
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if (dp[nx][ny][nmask] > dp[curr.x][curr.y][curr.mask] + 1) {
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dp[nx][ny][nmask] = dp[curr.x][curr.y][curr.mask] + 1;
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q.add(next);
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}
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}
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}
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}
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}
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}
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return -1;
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}
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public static void main(String[] args) {
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KillingZombies k = new KillingZombies();
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System.out.println(k.timeToKill(new String[] { "#######", "#H E #", "#######" }));
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System.out.println(k.timeToKill(
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new String[] { "#######", "# # # #", "## N##", "#W #", "#H# #", "#N ## #", "#######" }));
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System.out.println(k.timeToKill(
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new String[] { "#######", "## # ##", "# E##", "# S # #", "# E S #", "#H ##", "#######" }));
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}
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}

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