Data update

Task/Percolation-Bond-percolation/JavaScript/percolation-bond-percolation.js

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+// Constants
+const ROW_COUNT = 10;
+const COL_COUNT = 10;
+const FILL = 1;
+const RIGHT_WALL = 2;
+const LOWER_WALL = 4;
+
+// Global grid and endOfRow
+let grid = new Array(COL_COUNT * (ROW_COUNT + 2)).fill(0);
+let endOfRow = COL_COUNT;
+
+// Random number generator
+function random() {
+  return Math.random();
+}
+
+// Create the grid with walls based on probability
+function makeGrid(probability) {
+  grid.fill(0);
+  for (let i = 0; i < COL_COUNT; i++) {
+    grid[i] = LOWER_WALL | RIGHT_WALL;
+  }
+  endOfRow = COL_COUNT;
+  for (let i = 0; i < ROW_COUNT; i++) {
+    for (let j = COL_COUNT - 1; j >= 1; j--) {
+      const chance1 = random() < probability;
+      const chance2 = random() < probability;
+      grid[endOfRow++] = (chance1 ? LOWER_WALL : 0) | (chance2 ? RIGHT_WALL : 0);
+    }
+    const chance3 = random() < probability;
+    grid[endOfRow++] = RIGHT_WALL | (chance3 ? LOWER_WALL : 0);
+  }
+}
+
+// Display the grid in a readable format
+function showGrid() {
+  let output = "";
+  for (let j = 0; j < COL_COUNT; j++) {
+    output += "+--";
+  }
+  output += "+\n";
+
+  for (let i = 0; i < ROW_COUNT; i++) {
+    output += "|";
+    for (let j = 0; j < COL_COUNT; j++) {
+      const cell = grid[i * COL_COUNT + j + COL_COUNT];
+      output += (cell & FILL) ? "[]" : "  ";
+      output += (cell & RIGHT_WALL) ? "|" : " ";
+    }
+    output += "\n";
+
+    for (let j = 0; j < COL_COUNT; j++) {
+      const cell = grid[i * COL_COUNT + j + COL_COUNT];
+      output += (cell & LOWER_WALL) ? "+--" : "+  ";
+    }
+    output += "+\n";
+  }
+
+  output += " ";
+  for (let j = 0; j < COL_COUNT; j++) {
+    const cell = grid[ROW_COUNT * COL_COUNT + j + COL_COUNT];
+    output += (cell & FILL) ? "[]" : "  ";
+    output += (cell & RIGHT_WALL) ? "|" : " ";
+  }
+  output += "\n\n";
+  console.log(output);
+}
+
+// Iterative fill function using a stack
+function fill(startIndex) {
+  const stack = [startIndex];
+  while (stack.length > 0) {
+    const index = stack.pop();
+    if ((grid[index] & FILL) !== 0) continue;
+    grid[index] |= FILL;
+
+    // Check if we've reached the bottom
+    if (index >= grid.length - COL_COUNT) {
+      return true;
+    }
+
+    // Push neighbors onto the stack
+    if (index + COL_COUNT < grid.length && (grid[index] & LOWER_WALL) === 0) {
+      stack.push(index + COL_COUNT);
+    }
+    if (index + 1 < grid.length && (grid[index] & RIGHT_WALL) === 0) {
+      stack.push(index + 1);
+    }
+    if (index - 1 >= 0 && (grid[index - 1] & RIGHT_WALL) === 0) {
+      stack.push(index - 1);
+    }
+    if (index - COL_COUNT >= 0 && (grid[index - COL_COUNT] & LOWER_WALL) === 0) {
+      stack.push(index - COL_COUNT);
+    }
+  }
+  return false;
+}
+
+// Percolate function
+function percolate() {
+  for (let i = 0; i < COL_COUNT; i++) {
+    if (fill(COL_COUNT + i)) {
+      return true;
+    }
+  }
+  return false;
+}
+
+// Main simulation
+console.log(`Sample percolation with a ${COL_COUNT} x ${ROW_COUNT} grid:`);
+makeGrid(0.5);
+percolate();
+showGrid();
+
+console.log("Using 10,000 repetitions for each probability p:");
+for (let p = 1; p <= 9; p++) {
+  let percolationCount = 0;
+  const probability = p / 10.0;
+  for (let i = 0; i < 10000; i++) {
+    makeGrid(probability);
+    if (percolate()) {
+      percolationCount++;
+    }
+  }
+  const percolationProportion = percolationCount / 10000;
+  console.log(`p = ${probability.toFixed(1)}:  ${percolationProportion.toFixed(4)}`);
+}