Merge pull request #217 from 0xff-dev/master

Add solution and test-cases for problem 733

Author: Cori1109

leetcode/701-800/0733.Flood-Fill/README.md

@@ -1,28 +1,32 @@
 # [733.Flood Fill][title]
 
-> [!WARNING|style:flat]
-> This question is temporarily unanswered if you have good ideas. Welcome to [Create Pull Request PR](https://github.com/kylesliu/awesome-golang-algorithm)
-
 ## Description
+An image is represented by an `m x n` integer grid `image` where `image[i][j]` represents the pixel value of the image.
 
-**Example 1:**
+You are also given three integers `sr`, `sc`, and `newColor`. You should perform a __flood fill__ on the image starting from the pixel `image[sr][sc]`.
 
-```
-Input: a = "11", b = "1"
-Output: "100"
-```
+To perform a __flood fill__, consider the starting pixel, plus any pixels connected __4-directionally__ to the starting pixel of the same color as the starting pixel, plus any pixels connected __4-directionally__ to those pixels (also with the same color), and so on. Replace the color of all of the aforementioned pixels with `newColor`.
+
+Return the modified image after performing the flood fill.
 
-## 题意
-> ...
 
-## 题解
 
-### 思路1
-> ...
-Flood Fill
-```go
+**Example 1:**
+
+![flood1-grid](flood1-grid.jpg)
+
+```
+Input: image = [[1,1,1],[1,1,0],[1,0,1]], sr = 1, sc = 1, newColor = 2
+Output: [[2,2,2],[2,2,0],[2,0,1]]
+Explanation: From the center of the image with position (sr, sc) = (1, 1) (i.e., the red pixel), all pixels connected by a path of the same color as the starting pixel (i.e., the blue pixels) are colored with the new color.
+Note the bottom corner is not colored 2, because it is not 4-directionally connected to the starting pixel.
 ```
 
+__Example 2:__
+```
+Input: image = [[0,0,0],[0,0,0]], sr = 0, sc = 0, newColor = 2
+Output: [[2,2,2],[2,2,2]]
+```
 
 ## 结语
 

leetcode/701-800/0733.Flood-Fill/Solution.go

@@ -1,5 +1,30 @@
 package Solution
 
-func Solution(x bool) bool {
-	return x
+var localDirs = [][2]int{{0, -1}, {0, 1}, {-1, 0}, {1, 0}}
+
+func floodFillDFS(image, visited [][]int, sr, sc, rows, cols int, sourceColor, newColor int) {
+	if sr < 0 || sr >= rows || sc < 0 || sc >= cols {
+		return
+	}
+
+	if visited[sr][sc] > 0 || image[sr][sc] != sourceColor {
+		return
+	}
+
+	image[sr][sc] = newColor
+	visited[sr][sc] = 1
+	for _, dir := range localDirs {
+		floodFillDFS(image, visited, sr+dir[0], sc+dir[1], rows, cols, sourceColor, newColor)
+	}
+}
+
+func Solution(image [][]int, sr, sc, newColor int) [][]int {
+	rows, cols := len(image), len(image[0])
+	visited := make([][]int, len(image))
+	for idx := 0; idx < rows; idx++ {
+		visited[idx] = make([]int, cols)
+	}
+
+	floodFillDFS(image, visited, sr, sc, rows, cols, image[sr][sc], newColor)
+	return image
 }

leetcode/701-800/0733.Flood-Fill/Solution_test.go

@@ -9,31 +9,25 @@ import (
 func TestSolution(t *testing.T) {
 	//	测试用例
 	cases := []struct {
-		name   string
-		inputs bool
-		expect bool
+		name             string
+		inputs           [][]int
+		sr, sc, newColor int
+		expect           [][]int
 	}{
-		{"TestCase", true, true},
-		{"TestCase", true, true},
-		{"TestCase", false, false},
+		{"TestCase1", [][]int{{1, 1, 1}, {1, 1, 0}, {1, 0, 1}}, 1, 1, 2, [][]int{{2, 2, 2}, {2, 2, 0}, {2, 0, 1}}},
+		{"TestCase2", [][]int{{1}}, 0, 0, 2, [][]int{{2}}},
+		{"TestCase3", [][]int{{1, 1, 1}, {1, 0, 1}, {1, 1, 1}}, 1, 1, 2, [][]int{{1, 1, 1}, {1, 2, 1}, {1, 1, 1}}},
+		{"TestCase4", [][]int{{0, 0, 0}, {0, 0, 0}}, 0, 0, 2, [][]int{{2, 2, 2}, {2, 2, 2}}},
 	}
 
 	//	开始测试
 	for i, c := range cases {
 		t.Run(c.name+" "+strconv.Itoa(i), func(t *testing.T) {
-			got := Solution(c.inputs)
+			got := Solution(c.inputs, c.sr, c.sc, c.newColor)
 			if !reflect.DeepEqual(got, c.expect) {
-				t.Fatalf("expected: %v, but got: %v, with inputs: %v",
-					c.expect, got, c.inputs)
+				t.Fatalf("expected: %v, but got: %v, with inputs-image: %v, input-sr: %v, input-sc: %v",
+					c.expect, got, c.inputs, c.sr, c.sc)
 			}
 		})
 	}
 }
-
-//	压力测试
-func BenchmarkSolution(b *testing.B) {
-}
-
-//	使用案列
-func ExampleSolution() {
-}