Merge pull request #672 from 0xff-dev/2658

Add solution and test-cases for problem 2658

leetcode/2601-2700/2658.Maximum-Number-of-Fish-in-a-Grid/README.md

@@ -0,0 +1,43 @@
+# [2658.Maximum Number of Fish in a Grid][title]
+
+## Description
+You are given a **0-indexed** 2D matrix `grid` of size `m x n`, where `(r, c)` represents:
+
+- A **land** cell if `grid[r][c] = 0`, or
+- A **water** cell containing `grid[r][c]` fish, if `grid[r][c] > 0`.
+
+A fisher can start at any **water** cell `(r, c)` and can do the following operations any number of times:
+
+- Catch all the fish at cell `(r, c)`, or
+- Move to any adjacent **water** cell.
+
+Return the **maximum** number of fish the fisher can catch if he chooses his starting cell optimally, or `0` if no water cell exists.
+
+An **adjacent** cell of the cell `(r, c)`, is one of the cells `(r, c + 1), (r, c - 1), (r + 1, c) or (r - 1, c)` if it exists.
+
+**Example 1:**  
+
+![example1](./example.png)
+
+```
+Input: grid = [[0,2,1,0],[4,0,0,3],[1,0,0,4],[0,3,2,0]]
+Output: 7
+Explanation: The fisher can start at cell (1,3) and collect 3 fish, then move to cell (2,3) and collect 4 fish.
+```
+
+**Example 2:**  
+
+![example2](./example2.png)
+
+```
+Input: grid = [[1,0,0,0],[0,0,0,0],[0,0,0,0],[0,0,0,1]]
+Output: 1
+Explanation: The fisher can start at cells (0,0) or (3,3) and collect a single fish.
+```
+
+## 结语
+
+如果你同我一样热爱数据结构、算法、LeetCode，可以关注我 GitHub 上的 LeetCode 题解：[awesome-golang-algorithm][me]
+
+[title]: https://leetcode.com/problems/maximum-number-of-fish-in-a-grid/
+[me]: https://github.com/kylesliu/awesome-golang-algorithm

leetcode/2601-2700/2658.Maximum-Number-of-Fish-in-a-Grid/Solution.go

@@ -1,5 +1,32 @@
 package Solution
 
-func Solution(x bool) bool {
-	return x
+func Solution(grid [][]int) int {
+	m, n := len(grid), len(grid[0])
+	var dfs func(int, int, [][]bool) int
+	dfs = func(x, y int, visited [][]bool) int {
+		if x < 0 || x >= m || y < 0 || y >= n || grid[x][y] == 0 {
+			return 0
+		}
+		if visited[x][y] {
+			return 0
+		}
+		visited[x][y] = true
+		return grid[x][y] + dfs(x+1, y, visited) + dfs(x-1, y, visited) + dfs(x, y+1, visited) + dfs(x, y-1, visited)
+	}
+	ans := 0
+	for r := 0; r < m; r++ {
+		for c := 0; c < n; c++ {
+			if grid[r][c] == 0 {
+				continue
+			}
+			v := make([][]bool, m)
+			for i := 0; i < n; i++ {
+				v[i] = make([]bool, n)
+			}
+			if r := dfs(r, c, v); r > ans {
+				ans = r
+			}
+		}
+	}
+	return ans
 }

leetcode/2601-2700/2658.Maximum-Number-of-Fish-in-a-Grid/Solution_test.go

@@ -10,12 +10,21 @@ func TestSolution(t *testing.T) {
 	//	测试用例
 	cases := []struct {
 		name   string
-		inputs bool
-		expect bool
+		inputs [][]int
+		expect int
 	}{
-		{"TestCase", true, true},
-		{"TestCase", true, true},
-		{"TestCase", false, false},
+		{"TestCase1", [][]int{
+			{0, 2, 1, 0},
+			{4, 0, 0, 3},
+			{1, 0, 0, 4},
+			{0, 3, 2, 0},
+		}, 7},
+		{"TestCase2", [][]int{
+			{1, 0, 0, 0},
+			{0, 0, 0, 0},
+			{0, 0, 0, 0},
+			{0, 0, 0, 1},
+		}, 1},
 	}
 
 	//	开始测试
@@ -30,10 +39,10 @@ func TestSolution(t *testing.T) {
 	}
 }
 
-//	压力测试
+// 压力测试
 func BenchmarkSolution(b *testing.B) {
 }
 
-//	使用案列
+// 使用案列
 func ExampleSolution() {
 }