Queen's Attack II Discussions | Algorithms | HackerRank
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  3. Implementation
  4. Queen's Attack II
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Queen's Attack II

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982 Discussions

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  • bawa101001
     + 0 comments

    My Python solution: ' def queensAttack(n, k, r_q, c_q, obstacles): directions = [(1, 0), (-1, 0), (0, 1), (0, -1), (1, 1), (1, -1), (-1, 1), (-1, -1)] total = 0 # obstacles = set(obstacles) obstacles = set(tuple(obs) for obs in obstacles) for dx, dy in directions: x, y = r_q, c_q while True: x += dx y += dy if not (1 <= x <= n): break if not (1 <= y <= n): break if (x, y) in obstacles: break total += 1 return total

    '

  • logan_schultheis
     + 0 comments

    If you change the part of the code that reads the problem input to make a list of tuples as opposed to a list of lists, this will work on all test cases:

    def queensAttack(n, k, r_q, c_q, obstacles):
    directions = [(1, 0), (-1, 0), (0, 1), (0, -1), (1, 1), (1, -1), (-1, 1), (-1, -1)]
    total = 0
    obstacles = set(obstacles)
    for dx, dy in directions:
        x, y = r_q, c_q
        while True:
            x += dx
            y += dy
            if not (1 <= x <= n):
                break
            if not (1 <= y <= n):
                break
            if (x, y) in obstacles:
                break
            total += 1  
    return total

  • mustafeez0001
     + 0 comments

    EASIER JAVA SOLUTION;

    import java.util.*;

public final class Solution{
    public static void main(String[] args){
        int arraySize, qRow, qCol;
        
         HashSet<List<Integer>> s = new HashSet<>();
         try (Scanner in = new Scanner(System.in)) {
        
        arraySize = in.nextInt();
        int numberObstacles = in.nextInt();
         qRow= in.nextInt();
         qCol= in.nextInt();
         while(numberObstacles-->0){
             int obsRow = in.nextInt();
             int obsCol = in.nextInt();
             s.add(Arrays.asList(obsRow, obsCol));
         }
         }
         
         int position[][] = new int[][]{{0,1}, {1,0}, {-1,0},{0,-1}, {1,1},{-1,1},{1,-1},{-1,-1}}; 
         long ans=0;
         for(int i=0; i<position.length;i++){
             int row = qRow+position[i][0];
             int col = qCol+position[i][1];
             while(!s.contains(Arrays.asList(row, col))){
                //  System.out.println(s.contains(Arrays.asList(row, col)));
                //  System.out.printf("using:(%d,%d)==> %d, %d\n", position[i][0], position[i][0], row, col);
                 if( row <1 || row > arraySize){
                     break;
                 }
                 if( col <1 || col > arraySize){
                     break;
                 }
                 ans+=1;
                 
                 
                 row+=position[i][0];
                 col+=position[i][1];
             }
             
         }
             System.out.println(ans);
}
         
         
        COMMENT FOR PYTHON SOLUTION AS WELL
        
        
    }
}

  • CSAI_1520069
     + 0 comments

    def queensAttack(n, k, r_q, c_q, obstacles): # Create a set of obstacle positions obstacles = set(tuple(obstacle) for obstacle in obstacles)

    # Directions for the queen's movements
directions = [
    (1, 0),   # Down
    (-1, 0),  # Up
    (0, 1),   # Right
    (0, -1),  # Left
    (1, 1),   # Down-Right
    (1, -1),  # Down-Left
    (-1, 1),  # Up-Right
    (-1, -1)  # Up-Left
]

total = 0

for dx, dy in directions:
    x, y = r_q, c_q

    # Initialize the maximum reachable distance in this direction
    max_distance = n  # maximum distance to the edge of the board

    while True:
        x += dx
        y += dy

        # Check if the new position is within the board limits
        if not (1 <= x <= n and 1 <= y <= n):
            break

        # Check if there's an obstacle
        if (x, y) in obstacles:
            break

        total += 1  # Increment the count of positions the queen can attack

return total

  • CS_2212256_T
     + 1 comment
    import java.util.*;

public final class Solution {
  public static final void main(String[] args) {
    int n, rq, cq;
    Set<Long> o;
    try (Scanner in = new Scanner(System.in)) {
      n = in.nextInt();
      int k = in.nextInt();
      rq = in.nextInt();
      cq = in.nextInt();
      o = new HashSet<>(k);
      while (k --> 0) {
        int ro = in.nextInt(), co = in.nextInt();
        o.add((long)ro << 32 | co);
      }
    }
    int t = 0;
    for (int d[] : new int[][] {{-1, -1}, {-1,  0}, {-1, +1},
                                { 0, -1},           { 0, +1},
                                {+1, -1}, {+1,  0}, {+1, +1}}) {
      for (int r = rq + d[0], c = cq + d[1];
           1 <= r && r <= n && 1 <= c && c <= n && !o.contains((long)r << 32 | c);
           r += d[0], c += d[1]) {
        t++;
      }
    }
    System.out.println(t);
  }
}