1?泛洪填充算法(Flood Fill Algorithm)

泛洪填充算法(Flood Fill Algorithm) ，又稱(chēng)洪水填充算法，是在很多圖形繪制軟件中常用的填充算法，最熟悉不過(guò)就是 windows 自帶畫(huà)圖軟件的油漆桶功能。

2 源程序

using System;
using System.Collections;
using System.Collections.Generic;

namespace Legalsoft.Truffer.Algorithm
{
?? ?/// <summary>
?? ?/// 洪水填充算法
?? ?/// </summary>
?? ?public static partial class Algorithm_Gallery
?? ?{
?? ??? ?private static void Fill_4Directions(int[,] screen, int x, int y, int prevC, int newC)
?? ??? ?{
?? ??? ??? ?int M = screen.GetLength(0);
?? ??? ??? ?int N = screen.GetLength(1);

?? ??? ??? ?if (x < 0 || x >= M || y < 0 || y >= N)
?? ??? ??? ?{
?? ??? ??? ??? ?return;
?? ??? ??? ?}
?? ??? ??? ?if (screen[x, y] != prevC)
?? ??? ??? ?{
?? ??? ??? ??? ?return;
?? ??? ??? ?}
?? ??? ??? ?screen[x, y] = newC;
?? ??? ??? ?Fill_4Directions(screen, x + 1, y, prevC, newC);
?? ??? ??? ?Fill_4Directions(screen, x - 1, y, prevC, newC);
?? ??? ??? ?Fill_4Directions(screen, x, y + 1, prevC, newC);
?? ??? ??? ?Fill_4Directions(screen, x, y - 1, prevC, newC);
?? ??? ?}

?? ??? ?public static void Flood_Fill(int[,] screen, int x, int y, int newC)
?? ??? ?{
?? ??? ??? ?int prevC = screen[x, y];
?? ??? ??? ?if (prevC == newC)
?? ??? ??? ?{
?? ??? ??? ??? ?return;
?? ??? ??? ?}
?? ??? ??? ?Fill_4Directions(screen, x, y, prevC, newC);
?? ??? ?}
?? ?}
}

3 代碼格式

using System;
using System.Collections;
using System.Collections.Generic;namespace Legalsoft.Truffer.Algorithm
{/// <summary>/// 洪水填充算法/// </summary>public static partial class Algorithm_Gallery{private static void Fill_4Directions(int[,] screen, int x, int y, int prevC, int newC){int M = screen.GetLength(0);int N = screen.GetLength(1);if (x < 0 || x >= M || y < 0 || y >= N){return;}if (screen[x, y] != prevC){return;}screen[x, y] = newC;Fill_4Directions(screen, x + 1, y, prevC, newC);Fill_4Directions(screen, x - 1, y, prevC, newC);Fill_4Directions(screen, x, y + 1, prevC, newC);Fill_4Directions(screen, x, y - 1, prevC, newC);}public static void Flood_Fill(int[,] screen, int x, int y, int newC){int prevC = screen[x, y];if (prevC == newC){return;}Fill_4Directions(screen, x, y, prevC, newC);}}
}