动态规划：利用WarShell算法求有向图的传递闭包

  1 using  System;
  2 using  System.Collections.Generic;
  3 using  System.Text;
  4
  5 namespace  ConsoleApplication47
  6 {
  7    class Program
  8    {
  9        static void Main(string[] args)
 10        {
 11            WarShall ws = new WarShall(4);
 12
 13            ws.SetVaule(0, 1, true);
 14            ws.SetVaule(1, 3, true);
 15            ws.SetVaule(3, 0, true);
 16            ws.SetVaule(3, 2, true);
 17
 18            Console.WriteLine("Before:");
 19
 20            ws.Print();
 21
 22            bool[][] result = ws.GetMatrix();
 23
 24            Console.WriteLine("After:");
 25
 26            ws.Print();
 27
 28        }
 29
 30        class WarShall
 31        {
 32            bool[][] _matrix;
 33
 34            public WarShall(int n)
 35            {
 36                _matrix = new bool[n][];
 37
 38                for (int i = 0; i < n; i++)
 39                {
 40                    _matrix[i] = new bool[n];
 41                }
 42            }
 43
 44            public void SetVaule(int x, int y, bool vaule)
 45            {
 46                _matrix[x][y] = vaule;
 47            }
 48
 49            public bool[][] Matrix
 50            {
 51                get
 52                {
 53                    return _matrix;
 54                }
 55            }
 56
 57            public bool[][] GetMatrix()
 58            {
 59                for (int i = 0; i < _matrix.Length; i++)
 60                {
 61                    for (int x = 0; x < _matrix.Length; x++)
 62                    {
 63                        if (x == i)
 64                        {
 65                            continue;
 66                        }
 67
 68                        for (int y = 0; y < _matrix.Length; y++)
 69                        {
 70                            if (y == i)
 71                            {
 72                                continue;
 73                            }
 74
 75                            if (_matrix[x][i] && _matrix[i][y])
 76                            {
 77                                _matrix[x][y] = true;
 78                            }
 79                        }
 80                    }
 81                }
 82
 83
 84                return _matrix;
 85            }
 86
 87            public void Print()
 88            {
 89                for (int i = 0; i < _matrix.Length; i++)
 90                {
 91                    bool[] s = _matrix[i];
 92                    for (int j = 0; j < s.Length; j++)
 93                    {
 94                        Console.Write(s[j]);
 95                        Console.Write("  ");
 96                    }
 97                    Console.WriteLine();
 98                }
 99            }
100        }
101    }
102}
103