Data update

Task/Solve-a-Hidato-puzzle/JavaScript/solve-a-hidato-puzzle.js

@@ -0,0 +1,113 @@
+let board = [];
+let start = [];
+let given = [];
+
+function setup(input) {
+  /* This task is not about input validation, so
+     we're going to trust the input to be valid */
+  const puzzle = input.map(line => line.split(/\s+/));
+  const nCols = puzzle[0].length;
+  const nRows = puzzle.length;
+  let list = new Array(nRows * nCols);
+
+  board = Array(nRows + 2).fill().map(() =>
+    Array(nCols + 2).fill(-1)
+  );
+
+  for (let r = 0; r < nRows; r++) {
+    const row = puzzle[r];
+    for (let c = 0; c < nCols; c++) {
+      const cell = row[c];
+      switch (cell) {
+        case "_":
+          board[r + 1][c + 1] = 0;
+          break;
+        case ".":
+          break;
+        default:
+          const val = parseInt(cell, 10);
+          board[r + 1][c + 1] = val;
+          list.push(val);
+          if (val === 1) {
+            start = [r + 1, c + 1];
+          }
+          break;
+      }
+    }
+  }
+
+  list.sort((a, b) => a - b);
+  given = [...list];
+}
+
+function solve(r, c, n, next) {
+  if (n > given[given.length - 1]) {
+    return true;
+  }
+
+  const back = board[r][c];
+  if (back !== 0 && back !== n) {
+    return false;
+  }
+
+  if (back === 0 && given[next] === n) {
+    return false;
+  }
+
+  if (back === n) {
+    next++;
+  }
+
+  board[r][c] = n;
+  for (let i = -1; i < 2; i++) {
+    for (let j = -1; j < 2; j++) {
+      if (solve(r + i, c + j, n + 1, next)) {
+        return true;
+      }
+    }
+  }
+
+  board[r][c] = back;
+  return false;
+}
+
+function printBoard() {
+  for (const row of board) {
+    let rowStr = '';
+    for (const c of row) {
+      switch (true) {
+        case c === -1:
+          rowStr += ' . ';
+          break;
+        case c > 0:
+          rowStr += c.toString().padStart(2) + ' ';
+          break;
+        default:
+          rowStr += '__ ';
+          break;
+      }
+    }
+    console.log(rowStr);
+  }
+}
+
+function main() {
+  const input = [
+    "_ 33 35 _ _ . . .",
+    "_ _ 24 22 _ . . .",
+    "_ _ _ 21 _ _ . .",
+    "_ 26 _ 13 40 11 . .",
+    "27 _ _ _ 9 _ 1 .",
+    ". . _ _ 18 _ _ .",
+    ". . . . _ 7 _ _",
+    ". . . . . . 5 _"
+  ];
+
+  setup(input);
+  printBoard();
+  console.log("\nFound:");
+  solve(start[0], start[1], 1, 0);
+  printBoard();
+}
+
+main();