Contest 15 - Battleship - Peter Porter

[Peter Porter]

Here is my Battleship entry:
https://jsfiddle.net/dgewaLj0

Looking at my code, you wont see textareas for all the cells that make up the play area grid, because I had the script create them for me. Saved me the pain of manually hardcoding 100 individual textareas.

HTML

<div class="game-wrapper">
  <!-- Left: game board -->
  <div>
  <h1>Battleship</h1>

    <div id="game"></div>

    <div id="controls">
      <input type="text" id="coordInput" placeholder="e.g. A5" maxlength="3">
      <button onclick="fire()">Fire</button>
    </div>

    <p id="status">Chances left: 40 | Hits: 0 | Misses: 0 | Ships sunk: 0</p>
    <button id="restartBtn" style="display:none;" onclick="initGame()">Play Again</button>
  </div>

  <!-- Right: side column with textarea -->
  <div class="side-column">
    <textarea>
Objective:

Sink all of the hidden ships on the 10×10 grid before you run out of chances.

Fleet:

There are 5 ships of different lengths. They are placed randomly on the grid, either horizontally or vertically.
                                              
Taking a Shot:

Type the coordinate of the cell you want to target into the input box, for example:
A5 ? Column A, Row 5.

Press Enter on your keyboard or click the Fire button.

The cell will update, X ? you hit part of a ship, 0 ? you missed.

Below the input box you’ll see:
• Chances left
• Hits
• Misses
• Ships sunk
</textarea>
  </div>
</div>

Style

body {
    font-family: monospace;
    text-align: center;
    background-color: #f0f8ff;
  }

  table {
    border-collapse: collapse;
    margin: auto;
  }

  td {
    padding: 0;
    margin: 0;
    text-align: center;
  }

  .row-header {
    padding-right: 8px;  
    min-width: 25px;      
    text-align: right;    
  }

  textarea {
    resize: none;
    width: 30px;
    height: 30px;
    text-align: center;
    font-size: 18px;
    background-color: #add8e6; 
    border: none; /* no visible borders */
    margin-right: 5px;
    margin-bottom: 3px;
  }

  .miss {
    background-color: #add8e6; 
    color: white;

  .hit {
    background-color: #add8e6; 
    color: red;
  }

  #controls {
    margin-top: 20px;
  }

  .game-wrapper {
  display: flex; 
  justify-content: center;  
  gap: 10px;                  
  margin-top: 20px;
  height: 600px;
}

.side-column {
  background-color: #E0E0E0; 
  border-radius: 8px;         
  padding: 10px;              
  margin-top: 81px;
}

.side-column textarea {
  background-color: #E0E0E0; 
  width: 350px;
  height: 100%;
  resize: none;
  font-family: monospace;
  font-size: 14px;
  box-sizing: border-box;
  text-align: left;
}

Javascript

const SIZE = 10;  // Size of the board (10x10 grid)
const CHANCES = 40;  // Number of shots the player has
let grid = [];  // 2D array representing the board cells
let ships = [];  // Array holding all ships and their coordinates
let chancesLeft, hits, misses, sunk;  // Counters for game progress

// Initialize a new game
function initGame() {
  chancesLeft = CHANCES;
  hits = 0;
  misses = 0;
  sunk = 0;
  grid = Array.from({length: SIZE}, () => Array(SIZE).fill("~"));
  ships = [];
  placeShips();
  drawBoard();
  updateStatus();
  document.getElementById("restartBtn").style.display = "none";
}

// Draw the board as an HTML table
function drawBoard() {
  let html = "<table><tr><td></td>";
  for (let c=0; c<SIZE; c++) {
    html += `<td>${String.fromCharCode(65+c)}</td>`;
  }
  html += "</tr>";
  for (let r=0; r<SIZE; r++) {
    html += `<tr><td class="row-header">${r+1}</td>`;
    for (let c=0; c<SIZE; c++) {
      html += `<td><textarea id="cell-${r}-${c}" readonly>${grid[r][c]}</textarea></td>`;
    }
    html += "</tr>";
  }
  html += "</table>";
  document.getElementById("game").innerHTML = html;
}

// Update status line
  document.getElementById("status").innerText =
    `Chances left: ${chancesLeft} | Hits: ${hits} | Misses: ${misses} | Ships sunk: ${sunk}`;
}

// Handle firing at a coordinate
function fire() {
  let input = document.getElementById("coordInput").value.trim().toUpperCase();
  document.getElementById("coordInput").value = "";
  if (!/^[A-J](10|[1-9])$/.test(input)) {
    alert("Invalid coordinate! Use format like A5.");
    return;
  }
  let col = input.charCodeAt(0) - 65;
  let row = parseInt(input.slice(1)) - 1;
  let cell = document.getElementById(`cell-${row}-${col}`);

  if (cell.classList.contains("hit") || cell.classList.contains("miss")) {
    alert("Already targeted!");
    return;
  }

  let hitShip = ships.find(ship => ship.some(([r,c]) => r===row && c===col));
  if (hitShip) {
    cell.value = "X";
    cell.classList.add("hit");
    hits++;
    hitShip.hitCount = (hitShip.hitCount || 0) + 1;
    if (hitShip.hitCount === hitShip.length) {
      sunk++;
      alert("You sunk a ship!");
    }
    chancesLeft--; // <-- lose a chance even on a hit
  } else {
    cell.value = "0";
    cell.classList.add("miss");
    misses++;
    chancesLeft--;
}

  updateStatus();
  checkGameOver();
}

// Check win/lose conditions
function checkGameOver() {
  let totalShipCells = ships.reduce((sum, s) => sum + s.length, 0);
  if (hits === totalShipCells) {
    alert("You win!");
    document.getElementById("restartBtn").style.display = "inline";
  } else if (chancesLeft <= 0) {
    alert("Game over! You lose.");
    document.getElementById("restartBtn").style.display = "inline";
  }
}

// Randomly place ships
function placeShips() {
  const shipSizes = [2,3,3,4,5];
  for (let size of shipSizes) {
    let placed = false;
    while (!placed) {
      let orientation = Math.random() < 0.5 ? "H" : "V";
      let row = Math.floor(Math.random()*SIZE);
      let col = Math.floor(Math.random()*SIZE);
      let coords = [];
      for (let i=0; i<size; i++) {
        let r = row + (orientation==="V"?i:0);
        let c = col + (orientation==="H"?i:0);
        if (r>=SIZE || c>=SIZE) { coords=[]; break; }
        coords.push([r,c]);
      }
      if (coords.length===size && validPlacement(coords)) {
        ships.push(coords);
        placed = true;
      }
    }
  }
}

// Ensure ships don't overlap or touch
function validPlacement(coords) {
  for (let [r,c] of coords) {
    for (let dr=-1; dr<=1; dr++) {
      for (let dc=-1; dc<=1; dc++) {
        let nr=r+dr, nc=c+dc;
        if (nr>=0 && nr<SIZE && nc>=0 && nc<SIZE) {
          if (ships.some(ship => ship.some(([sr,sc]) => sr===nr && sc===nc))) {
            return false;
          }
        }
      }
    }
  }
  return true;
}

// Allow Enter key to fire
document.getElementById("coordInput").addEventListener("keydown", e => {
  if (e.key==="Enter") fire();
});

// Start game on load
initGame();

[2kaud]

Shouldn't contest submissions be private until after the contest closes?


This is a hidden post waiting to be moderated. (steve)