Word Search

Author: casentino

word-search/casentino.ts

@@ -0,0 +1,44 @@
+function exist(board: string[][], word: string): boolean {
+  const m = board.length;
+  const n = board[0].length;
+
+  const visited = Array.from({ length: m }, () => new Array(n).fill(0));
+  function findDirection(currentI: number, currentJ: number, findNextIdx: number) {
+    if (findNextIdx === word.length) {
+      return true;
+    }
+    if (
+      currentI < 0 ||
+      currentJ < 0 ||
+      currentI >= m ||
+      currentJ >= n ||
+      board[currentI][currentJ] !== word[findNextIdx]
+    ) {
+      return false;
+    }
+    if (visited[currentI][currentJ] === 1) {
+      return false;
+    }
+    visited[currentI][currentJ] = 1;
+
+    const isApproachLastWord =
+      findDirection(currentI + 1, currentJ, findNextIdx + 1) ||
+      findDirection(currentI - 1, currentJ, findNextIdx + 1) ||
+      findDirection(currentI, currentJ - 1, findNextIdx + 1) ||
+      findDirection(currentI, currentJ + 1, findNextIdx + 1);
+
+    if (!isApproachLastWord) {
+      visited[currentI][currentJ] = 0;
+    }
+    return isApproachLastWord;
+  }
+  for (let i = 0; i < m; i++) {
+    for (let j = 0; j < n; j++) {
+      const result = findDirection(i, j, 0);
+      if (result) {
+        return true;
+      }
+    }
+  }
+  return false;
+}