不相交集类应用：迷宫生成

#include <iostream>
#include <vector>
#include <cstdlib>
#include <ctime>

#define N 100

using namespace std;

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

class DisjSets
{
public:
explicit DisjSets(int numElements);

int find(int x) const;
void unionSets(int node1, int node2);
bool connected(int node1, int node2) const
{
return find(node1) == find(node2);
}

private:
vector<int> s;
};

DisjSets::DisjSets(int numElements):s(numElements)
{
for (int i = 0; i < s.size(); i++)
s[i] = -1;
}

int DisjSets::find(int x) const
{
if (s[x] < 0)
return x;
else
return find(s[x]);
}

void DisjSets::unionSets(int node1, int node2)
{
int root1 = find(node1);
int root2= find(node2);

if (root1==root2)
return;

if (s[root2] < s[root1])
s[root1] = root2;
else
{
if(s[root1] == s[root2])
s[root1]--;
s[root2] = root1;
}
}

void fill(int value)
{
int i,j;
for(i=0; i<N+1; i++)
for(j=0; j<N; j++)
wall_row[i][j] = value;
for(i=0; i<N; i++)
for(j=0; j<N+1; j++)
wall_col[i][j] = value;
}

void print()
{
int i, j;
for (i=0; i<N+1; i++)
{
for (j=0; j<N+1; j++)
{
if (i > 0)
{
if(wall_col[i-1][j])
cout<<"|";
else
cout<<" ";
}
if (j<N)
{
if (i>0)
{
if (wall_row[i][j])
cout<<"_";
else
cout<<" ";
}
else
{
if(wall_row[i][j])
cout<<" _";
else
cout<<"  ";
}
}
}
cout<<endl;
}
}

void map_rand(int x, int &type, int &a, int &b)
{
type = 0;
if(x >= N*(N-1))
type = 1;
if(type == 0)
{
a = x / (N - 1);
b = x % (N - 1) + 1;
}
else
{
x -= N*(N-1);
a = x / N + 1;
b = x % N;
}
}

void map_pos(int type, int a, int b, int &node1, int &node2)
{
if(type == 0)
{
node1 = a * N + b - 1;
node2 = a * N + b;
} else
{
node1 = (a - 1) * N + b;
node2 = (a - 1) * N + b + N;
}
}

int randselect(void)
{
int range = N*(N-1)*2;
return rand() % range;
}

int main()
{
fill(1); //赋值全部为1
srand(time(0));
wall_row[0][0] = 0;
wall_col[0][0] = 0;
wall_row
[N-1] = 0;
wall_col[N-1]
= 0;//定义出口入口

int amount = N * N;

DisjSets s(amount);

while(!s.connected(0, amount-1)) //是否两个节点相连（相同）
{
int type, a, b;
do
{
int wall = randselect();
map_rand(wall, type, a, b);
}
while ((type == 0 && wall_col[a][b] == 0) ||(type == 1 && wall_row[a][b] == 0))
;
int node1, node2;
map_pos(type, a, b, node1, node2);
if(!s.connected(node1, node2))
{
if(type == 0)
wall_col[a][b] = 0;
else
wall_row[a][b] = 0;
s.unionSets(node1, node2);
}
}
print();
return 0;
}