不相交集类应用：迷宫生成

  1 #include <iostream>

  2 #include <vector>

  3 #include <cstdlib>

  4 #include <ctime>

  5 

  6 #define N 100

  7 

  8 using namespace std;

  9 

 10 int wall_row[N+1][N];

 11 int wall_col[N][N+1];

 12 

 13 class DisjSets

 14 {

 15 public:

 16   explicit DisjSets(int numElements);

 17 

 18   int find(int x) const;

 19   void unionSets(int node1, int node2);

 20   bool connected(int node1, int node2) const

 21   {

 22     return find(node1) == find(node2);

 23   }

 24 

 25 private:

 26   vector<int> s;

 27 };

 28 

 29 DisjSets::DisjSets(int numElements):s(numElements)

 30 {

 31   for (int i = 0; i < s.size(); i++)

 32     s[i] = -1;

 33 }

 34 

 35 int DisjSets::find(int x) const

 36 {

 37   if (s[x] < 0)

 38     return x;

 39   else

 40     return find(s[x]);

 41 }

 42 

 43 void DisjSets::unionSets(int node1, int node2)

 44 {

 45   int root1 = find(node1);

 46   int root2= find(node2);

 47 

 48   if (root1==root2)

 49     return;

 50 

 51   if (s[root2] < s[root1])

 52     s[root1] = root2;

 53   else 

 54   {

 55     if(s[root1] == s[root2])

 56       s[root1]--;

 57     s[root2] = root1;

 58   }

 59 }

 60 

 61 void fill(int value)

 62 {

 63   int i,j;

 64   for(i=0; i<N+1; i++)

 65     for(j=0; j<N; j++)

 66       wall_row[i][j] = value;

 67   for(i=0; i<N; i++)

 68     for(j=0; j<N+1; j++)

 69       wall_col[i][j] = value;

 70 }

 71 

 72 void print()

 73 {

 74   int i, j;

 75   for (i=0; i<N+1; i++) 

 76   {

 77     for (j=0; j<N+1; j++) 

 78     {

 79         if (i > 0)

 80         {

 81             if(wall_col[i-1][j])

 82               cout<<"|";

 83             else

 84               cout<<" ";

 85         }

 86         if (j<N)

 87         {

 88             if (i>0)

 89             {

 90               if (wall_row[i][j])

 91                 cout<<"_";

 92               else

 93                 cout<<" ";

 94             }

 95             else

 96             {

 97               if(wall_row[i][j])

 98                 cout<<" _";

 99               else

100                 cout<<"  ";

101             }

102         }

103     }

104     cout<<endl;

105   }

106 }

107 

108 void map_rand(int x, int &type, int &a, int &b)

109 {

110   type = 0;

111   if(x >= N*(N-1)) 

112       type = 1;

113   if(type == 0) 

114   {

115     a = x / (N - 1);

116     b = x % (N - 1) + 1;

117   } 

118   else 

119   {

120     x -= N*(N-1);

121     a = x / N + 1;

122     b = x % N;

123   }

124 }

125 

126 void map_pos(int type, int a, int b, int &node1, int &node2)

127 {

128   if(type == 0) 

129   {

130     node1 = a * N + b - 1;

131     node2 = a * N + b;

132   } else 

133   {

134     node1 = (a - 1) * N + b;

135     node2 = (a - 1) * N + b + N;

136   }

137 }

138 

139 int randselect(void)

140 {

141   int range = N*(N-1)*2;

142   return rand() % range;

143 }

144 

145 int main()

146 {

147   fill(1); //赋值全部为1

148   srand(time(0));

149   wall_row[0][0] = 0;

150   wall_col[0][0] = 0;

151   wall_row[N][N-1] = 0;

152   wall_col[N-1][N] = 0;//定义出口入口

153 

154   int amount = N * N;

155 

156   DisjSets s(amount);

157 

158   while(!s.connected(0, amount-1)) //是否两个节点相连（相同）

159   {

160     int type, a, b;

161     do 

162     {

163       int wall = randselect();

164       map_rand(wall, type, a, b);

165     } 

166     while ((type == 0 && wall_col[a][b] == 0) ||(type == 1 && wall_row[a][b] == 0))

167         ;

168     int node1, node2;

169     map_pos(type, a, b, node1, node2);

170     if(!s.connected(node1, node2)) 

171     {

172       if(type == 0)

173         wall_col[a][b] = 0;

174       else

175         wall_row[a][b] = 0;

176       s.unionSets(node1, node2);

177     }

178   }

179   print();

180   return 0;

181 }

生成结果“