Create 864-shortest-path-to-get-all-keys.js

Author: everthis

864-shortest-path-to-get-all-keys.js

@@ -0,0 +1,60 @@
+/**
+ * @param {string[]} grid
+ * @return {number}
+ */
+const shortestPathAllKeys = function(grid) {
+  let r = grid.length,
+    c = grid[0].length
+  let moves = [[-1, 0], [1, 0], [0, 1], [0, -1]]
+  let finalState = 0,
+    startPoint = null
+  for (let i = 0; i < r; i++) {
+    for (let j = 0; j < c; j++) {
+      let code = grid[i].charCodeAt(j) - 97
+      if (code >= 0 && code <= 5) {
+        finalState = finalState | (1 << code)
+      } else if (grid[i][j] === '@') {
+        startPoint = [i, j]
+      }
+    }
+  }
+  let visited = Array(finalState + 1)
+    .fill()
+    .map(() =>
+      Array(r)
+        .fill()
+        .map(() => Array(c).fill(false))
+    )
+  let step = 0
+  let arr = [[startPoint[0], startPoint[1], 0]]
+  while (arr.length > 0) {
+    let len = arr.length
+    for (let i = 0; i < len; i++) {
+      let [x, y, keysState] = arr.shift()
+      for (let [dx, dy] of moves) {
+        let newx = x + dx,
+          newy = y + dy
+        if (newx < 0 || newy < 0 || newx >= r || newy >= c) continue
+        let curstr = grid[newx][newy]
+        if (curstr === '#') continue
+        let code = grid[newx].charCodeAt(newy)
+        if (visited[keysState][newx][newy]) continue
+        visited[keysState][newx][newy] = true
+        if (code >= 65 && code <= 72 && ((1 << (code - 65)) & keysState) === 0)
+          continue
+        let newState = keysState
+        if (
+          code >= 97 &&
+          code <= 102 &&
+          ((1 << (code - 97)) & keysState) === 0
+        ) {
+          newState = newState | (1 << (code - 97))
+          if (newState === finalState) return step + 1
+        }
+        arr.push([newx, newy, newState])
+      }
+    }
+    step++
+  }
+  return -1
+}