Add solution #1368

Author: JoshCrozier

1368-minimum-cost-to-make-at-least-one-valid-path-in-a-grid.js

@@ -0,0 +1,50 @@
+/**
+ * 1368. Minimum Cost to Make at Least One Valid Path in a Grid
+ * https://leetcode.com/problems/minimum-cost-to-make-at-least-one-valid-path-in-a-grid/
+ * Difficulty: Hard
+ *
+ * Given an m x n grid. Each cell of the grid has a sign pointing to the next cell you should
+ * visit if you are currently in this cell. The sign of grid[i][j] can be:
+ * - 1 which means go to the cell to the right. (i.e go from grid[i][j] to grid[i][j + 1])
+ * - 2 which means go to the cell to the left. (i.e go from grid[i][j] to grid[i][j - 1])
+ * - 3 which means go to the lower cell. (i.e go from grid[i][j] to grid[i + 1][j])
+ * - 4 which means go to the upper cell. (i.e go from grid[i][j] to grid[i - 1][j])
+ *
+ * Notice that there could be some signs on the cells of the grid that point outside the grid.
+ *
+ * You will initially start at the upper left cell (0, 0). A valid path in the grid is a path
+ * that starts from the upper left cell (0, 0) and ends at the bottom-right cell (m - 1, n - 1)
+ * following the signs on the grid. The valid path does not have to be the shortest.
+ *
+ * You can modify the sign on a cell with cost = 1. You can modify the sign on a cell one time
+ * only.
+ *
+ * Return the minimum cost to make the grid have at least one valid path.
+ */
+
+/**
+ * @param {number[][]} grid
+ * @return {number}
+ */
+var minCost = function(grid) {
+  const queue = [[0, 0]];
+  const directions = [[0, 1, 1], [0, -1, 2], [1, 0, 3], [-1, 0, 4]];
+  const bfs = grid.map(r => r.map(_ => Infinity));
+  bfs[0][0] = 0;
+
+  while (queue.length > 0) {
+    const [x, y] = queue.shift();
+    for (const [dx, dy, value] of directions) {
+      const [cX, cY] = [x + dx, y + dy];
+      if (grid[cX]?.[cY]) {
+        const updatedValue = bfs[x][y] + (grid[x][y] !== value);
+        if (updatedValue < bfs[cX][cY]) {
+          bfs[cX][cY] = updatedValue;
+          queue.push([cX, cY]);
+        }
+      }
+    }
+  }
+
+  return bfs.at(-1).at(-1);
+};

README.md

@@ -345,6 +345,7 @@
 1356|[Sort Integers by The Number of 1 Bits](./1356-sort-integers-by-the-number-of-1-bits.js)|Easy|
 1360|[Number of Days Between Two Dates](./1360-number-of-days-between-two-dates.js)|Easy|
 1365|[How Many Numbers Are Smaller Than the Current Number](./1365-how-many-numbers-are-smaller-than-the-current-number.js)|Easy|
+1368|[Minimum Cost to Make at Least One Valid Path in a Grid](./1368-minimum-cost-to-make-at-least-one-valid-path-in-a-grid.js)|Hard|
 1374|[Generate a String With Characters That Have Odd Counts](./1374-generate-a-string-with-characters-that-have-odd-counts.js)|Easy|
 1380|[Lucky Numbers in a Matrix](./1380-lucky-numbers-in-a-matrix.js)|Easy|
 1389|[Create Target Array in the Given Order](./1389-create-target-array-in-the-given-order.js)|Easy|