add sol

leetcode/daily/1368/sol.go

@@ -0,0 +1,84 @@
+// https://leetcode.com/problems/minimum-cost-to-make-at-least-one-valid-path-in-a-grid/description/
+
+package main
+
+import (
+	"container/list"
+	"fmt"
+)
+
+func minCost(grid [][]int) int {
+	m, n := len(grid), len(grid[0])
+	// define directions
+	dirs := [4][2]int{
+		{0, 1},  // right
+		{0, -1}, // left
+		{1, 0},  // down
+		{-1, 0}, // up
+	}
+
+	// init cost
+	costs := make([][]int, m)
+	for i := range costs {
+		costs[i] = make([]int, n)
+		for j := range costs[i] {
+			costs[i][j] = 1 << 30
+		}
+	}
+	costs[0][0] = 0 // start point cost is 0
+
+	// define dqueue
+	dq := list.New()
+	dq.PushBack([3]int{0, 0, 0}) // [x, y, cost]
+
+	// bfs
+	for dq.Len() > 0 {
+		node := dq.Remove(dq.Front()).([3]int)
+		x, y, cost := node[0], node[1], node[2]
+
+		// if reach the end point, return the cost
+		if x == m-1 && y == n-1 {
+			return cost
+		}
+
+		// try all directions
+		for i, dir := range dirs {
+			nx, ny := x+dir[0], y+dir[1]
+			if nx >= 0 && nx < m && ny >= 0 && ny < n { // Nếu ô mới nằm trong lưới
+				newCost := cost
+				if grid[x][y] != i+1 { // Nếu hướng sai, tăng chi phí
+					newCost++
+				}
+
+				// Nếu tìm được đường đi với chi phí thấp hơn
+				if newCost < costs[nx][ny] {
+					costs[nx][ny] = newCost
+					if grid[x][y] == i+1 {
+						dq.PushFront([3]int{nx, ny, newCost}) // Ưu tiên chi phí 0
+					} else {
+						dq.PushBack([3]int{nx, ny, newCost}) // Chi phí 1 thêm vào sau
+					}
+				}
+			}
+		}
+	}
+
+	return -1
+}
+
+func main() {
+	grid1 := [][]int{
+		{1, 1, 3},
+		{3, 2, 2},
+		{1, 1, 4},
+	}
+	fmt.Println(minCost(grid1)) // Output: 0
+
+	grid2 := [][]int{
+		{1, 1, 1, 1},
+		{2, 2, 2, 2},
+		{1, 1, 1, 1},
+		{2, 2, 2, 2},
+	}
+	fmt.Println(minCost(grid2)) // Output: 3
+}