不相交集類應用：迷宮生成

 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); //賦值所有爲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;//定義出口入口
153 
154   int amount = N * N; 155 
156  DisjSets s(amount); 157 
158   while(!s.connected(0, amount-1)) //是否兩個節點相連（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 }

生成結果「