Update 1263-minimum-moves-to-move-a-box-to-their-target-location.js

Author: everthis

1263-minimum-moves-to-move-a-box-to-their-target-location.js

@@ -1,3 +1,99 @@
+/**
+ * @param {character[][]} grid
+ * @return {number}
+ */
+const minPushBox = function (grid) {
+  let box, person, target
+  const m = grid.length,
+    n = grid[0].length
+  const dirs = [
+    [-1, 0],
+    [1, 0],
+    [0, -1],
+    [0, 1],
+  ]
+  for (let i = 0; i < m; i++) {
+    for (let j = 0; j < n; j++) {
+      const e = grid[i][j]
+      if (e === 'B') box = [i, j]
+      else if (e === 'T') target = [i, j]
+      else if (e === 'S') person = [i, j]
+    }
+  }
+
+  const valid = ([i, j]) => {
+    return i >= 0 && i < m && j >= 0 && j < n && grid[i][j] !== '#'
+  }
+  const key = ([i, j]) => `${i},${j}`
+
+  const chk = (person, newPerson, box) => {
+    const set = new Set()
+    set.add(key(box))
+    let q = [person]
+    while (q.length) {
+      const tmp = []
+      const size = q.length
+      for (let i = 0; i < size; i++) {
+        const [x, y] = q[i]
+        if (key([x, y]) === key(newPerson)) return true
+        for (const [dx, dy] of dirs) {
+          const [nx, ny] = [x + dx, y + dy]
+          if (valid([nx, ny]) && !set.has(key([nx, ny]))) {
+            set.add(key([nx, ny]))
+            tmp.push([nx, ny])
+          }
+        }
+      }
+      q = tmp
+    }
+    return false
+  }
+
+
+  let q = [[0, box, person]]
+  const dkey = (a, b) => `${a[0]},${a[1]}_${b[0]},${b[1]}`
+  const set = new Set()
+  set.add(dkey(box, person))
+  while (q.length) {
+    const size = q.length
+    const tmp = []
+    for (let i = 0; i < size; i++) {
+      const [v, b, p] = q[i]
+      if (key(b) === key(target)) return v
+      const bArr = [
+        [b[0], b[1] + 1],
+        [b[0], b[1] - 1],
+        [b[0] + 1, b[1]],
+        [b[0] - 1, b[1]],
+      ]
+      const pArr = [
+        [b[0], b[1] - 1],
+        [b[0], b[1] + 1],
+        [b[0] - 1, b[1]],
+        [b[0] + 1, b[1]],
+      ]
+
+      for (let j = 0; j < 4; j++) {
+        const nb = bArr[j],
+          np = pArr[j]
+        const nk = dkey(nb, b)
+
+        if (set.has(nk)) continue
+        if (valid(nb) && valid(np) && chk(p, np, b)) {
+          tmp.push([v + 1, nb, b])
+          set.add(nk)
+        }
+      }
+    }
+    q = tmp
+  }
+
+  return -1
+}
+
+// another
+
+
 /**
  * @param {character[][]} grid
  * @return {number}