Create Solution.js

Author: 07subhadip

solution/2500-2599/2577.Minimum Time to Visit a Cell In a Grid/Solution.js

@@ -0,0 +1,101 @@
+class MinHeap {
+    constructor() {
+        this.heap = [];
+    }
+
+    push(element) {
+        this.heap.push(element);
+        this._heapifyUp();
+    }
+
+    pop() {
+        if (this.size() === 1) return this.heap.pop();
+        const top = this.heap[0];
+        this.heap[0] = this.heap.pop();
+        this._heapifyDown();
+        return top;
+    }
+
+    peek() {
+        return this.heap[0];
+    }
+
+    size() {
+        return this.heap.length;
+    }
+
+    _heapifyUp() {
+        let index = this.heap.length - 1;
+        while (index > 0) {
+            const parentIndex = Math.floor((index - 1) / 2);
+            if (this.heap[index][0] >= this.heap[parentIndex][0]) break;
+            [this.heap[index], this.heap[parentIndex]] = [this.heap[parentIndex], this.heap[index]];
+            index = parentIndex;
+        }
+    }
+
+    _heapifyDown() {
+        let index = 0;
+        const length = this.heap.length;
+        while (true) {
+            const leftChild = 2 * index + 1;
+            const rightChild = 2 * index + 2;
+            let smallest = index;
+
+            if (leftChild < length && this.heap[leftChild][0] < this.heap[smallest][0]) {
+                smallest = leftChild;
+            }
+            if (rightChild < length && this.heap[rightChild][0] < this.heap[smallest][0]) {
+                smallest = rightChild;
+            }
+            if (smallest === index) break;
+
+            [this.heap[index], this.heap[smallest]] = [this.heap[smallest], this.heap[index]];
+            index = smallest;
+        }
+    }
+}
+
+/**
+ * @param {number[][]} grid
+ * @return {number}
+ */
+var minimumTime = function(grid) {
+    const m = grid.length;
+        const n = grid[0].length;
+
+        if (grid[0][1] > 1 && grid[1][0] > 1) return -1;
+
+        const dist = Array.from({ length: m }, () => Array(n).fill(Infinity));
+        dist[0][0] = 0;
+
+        const pq = new MinHeap();
+        pq.push([0, 0, 0]);
+
+        const directions = [-1, 0, 1, 0, -1];
+
+        while (pq.size() > 0) {
+            const [t, i, j] = pq.pop();
+
+            if (i === m - 1 && j === n - 1) return t;
+
+            for (let d = 0; d < 4; d++) {
+                const x = i + directions[d];
+                const y = j + directions[d + 1];
+
+                if (x >= 0 && x < m && y >= 0 && y < n) {
+                    let nt = t + 1;
+                    if (nt < grid[x][y]) {
+                        nt = grid[x][y] + (grid[x][y] - nt) % 2;
+                    }
+
+                    if (nt < dist[x][y]) {
+                        dist[x][y] = nt;
+                        pq.push([nt, x, y]);
+                    }
+                }
+            }
+        }
+
+        return -1;
+};