【POJ1208】The Blocks Problem

最新推荐文章于 2020-07-16 17:04:07 发布

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最新推荐文章于 2020-07-16 17:04:07 发布

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原文链接：http://www.cnblogs.com/tuty/archive/2010/09/27/1836596.html

本文介绍了一种解决木块问题的算法实现，通过定义函数f(i)将木块i上的其他木块放回初始位置，m(i,j)将木块i及以上的木块移动到包含j的上方等操作来实现木块的移动与堆叠。

来源：The Blocks Problem

推导：（略）

设计：

　　f(i): 把叠在木块i上的其他木块放回初始位置.

　　m(i,j): 把i及其以上的木块全叠到包含j的上方.

　　move a onto b => f(a),f(b),m(a,b)

　　move a over b => f(a),m(a,b)

　　pile a onto b => f(b),m(a,b)

　　pile a over b => m(a,b)

代码：

#include < iostream >
using namespace std;

#define N 24

// 块
struct Node{
int No; // 编号
struct Node * next;
};

struct Node * station[N]; // 原始的块位置
int place[N]; // 当前各块所在的位置

struct Node * Find( int i, bool setNULL)
{
struct Node * p, * q;
int j = place[i];
if (station[j] -> No == i)
{
p = station[j];
if (setNULL)
station[j] = NULL;
return p;
}
else
{
q = station[j];
p = q -> next;
while (p -> No != i)
{
q = p;
p = q -> next;
}
if (setNULL)
q -> next = NULL;
return p;
}
}

void F( int i)
{
struct Node * p;
p = Find(i, false );

if (p -> next == NULL)
return ;

int j;
while (p -> next != NULL)
{
j = p -> next -> No;
station[j] = p -> next;
place[j] = j;
p -> next = NULL;
p = station[j];
}
}

void M( int i, int j)
{
if ( i == j || place[i] == place[j] )
return ;

struct Node * p, * q;
p = Find(i, true );
q = Find(j, false );

while (q -> next != NULL)
q = q -> next;

q -> next = p;

while (p != NULL)
{
place[p -> No] = place[q -> No];
p = p -> next;
}

}

void MoveAOntoB( int i, int j)
{
F(i);
F(j);
M(i,j);
}

void MoveAOverB( int i, int j)
{
F(i);
M(i,j);
}

void PileAOntoB( int i, int j)
{
F(j);
M(i,j);
}

void PileAOverB( int i, int j)
{
M(i,j);
}

void Init()
{
for ( int i = 0 ;i < N;i ++ )
{
place[i] = i;
station[i] = ( struct Node * )malloc( sizeof ( struct Node));
station[i] -> No = i;
station[i] -> next = NULL;
}

}

int main()
{
int n;
char ch1[ 5 ],ch2[ 5 ];
int a,b;
struct Node * p;
cin >> n;
Init();
while (cin >> ch1 && strcmp(ch1, " quit " ) != 0 )
{
cin >> a;
cin >> ch2;
cin >> b;
if ( strcmp(ch1, " move " ) == 0 )
{
if ( strcmp(ch2, " onto " ) == 0 )
MoveAOntoB(a,b);
else
MoveAOverB(a,b);
}
else
{
if ( strcmp(ch2, " onto " ) == 0 )
PileAOntoB(a,b);
else
PileAOverB(a,b);
}
}

for ( int i = 0 ;i < n;i ++ )
{
cout << i << " : " ;
p = station[i];
while (p != NULL)
{
cout << p -> No << " " ;
p = p -> next;
}
cout << endl;
}

return 1 ;
}

转载于:https://www.cnblogs.com/tuty/archive/2010/09/27/1836596.html