HDU 2295 (the bare DLX times out and requires pruning)

 

When Judge () is used, if depth + judge () is greater than count, false is directly returned;

 

# Include <iostream>

# Include <cmath>

# Include <stdio. h>

Using namespace std;

 

Const int n= 100;

Struct node {

Int L, R, D, U, col;

} Dia [N * N];

Double map [N] [N];

Int Size [N];

 

Pair <double, double> city [N], Radar [N];

 

Int n, m, count;

Void makegraph (double mid)

{

Int I, j, now, pre, RP;

///// Initialize the header pointer ///////////

For (I = 0; I <= n; I ++)

{

Dia [I]. col = I;

Dia [I]. D = dia [I]. U = I;

Dia [I]. L = I-1;

Dia [I]. R = I + 1;

Size [I] = 0;

}

Dia [0]. L = n; dia [n]. R = 0;

Now = n + 1;

For (I = 1; I <= m; I ++)

{

RP = pre = now; // RP row pointer

For (j = 1; j <= n; j ++)

If (map [I] [j] <mid ){

Dia [now]. col = j; // column number

Size [j] ++;

 

Dia [now]. U = dia [j]. U;

Dia [now]. D = j;

Dia [dia [j]. U]. D = now;

Dia [j]. U = now;

 

Dia [now]. L = pre;

Dia [now]. R = RP;

Dia [pre]. R = now;

Dia [RP]. L = now;

Pre = now ++;

}

}

}

 

Void Cover (int c)

{

// Dia [dia [c]. R]. L = dia [c]. L;

// Dia [dia [c]. L]. R = dia [c]. R;

For (int I = dia [c]. D; I! = C; I = dia [I]. D)

{

Dia [dia [I]. L]. R = dia [I]. R;

Dia [dia [I]. R]. L = dia [I]. L;

Size [dia [I]. col] --;

}

}

Void Recover (int c)

{

For (int I = dia [c]. U; I! = C; I = dia [I]. U)

// For (int j = dia [I]. L; j! = I; j = dia [j]. L)

{

Dia [dia [I]. L]. R = I;

Dia [dia [I]. R]. L = I;

Size [dia [I]. col] ++;

}

// Dia [dia [c]. R]. L = c;

// Dia [dia [c]. L]. R = c;

}

 

Int judge ()

{

Int hash [N] = {0 };

Int ans = 0, I, j, k;

For (I = dia [0]. R; I = dia [I]. R)

If (! Hash [I])

{

Ans ++;

Hash [I] = 1;

For (j = dia [I]. D; j! = I; j = dia [j]. D)

For (k = dia [j]. R; k! = J; k = dia [k]. R)

Hash [dia [k]. col] = 1;

}

Return ans;

}

Bool Algorithm_X (int depth)

{

Int I, j;

If (depth + judge ()> count)

// If (depth> count)

Return false;

If (dia [0]. R = 0)

Return true;

 

Int mi = 0 xfffffff, c_pos;

For (I = dia [0]. R; I! = 0; I = dia [I]. R)

If (mi> Size [I]) {

Mi = Size [I];

C_pos = I;

If (mi = 1) break;

}

// If (Size [c_pos] = 0) return false;

// Cover (c_pos );

For (I = dia [c_pos]. D; I! = C_pos; I = dia [I]. D)

{

Cover (I );

For (j = dia [I]. R; j! = I; j = dia [j]. R)

Cover (j );

If (Algorithm_X (depth + 1 ))

Return true;

For (j = dia [I]. L; j! = I; j = dia [j]. L)

Recover (j );

Recover (I );

}

// Recover (c_pos );

Return false;

}

 

Void Init (double & ma)

{

Int I, j;

For (I = 1; I <= m; I ++)

For (j = 1; j <= n; j ++)

{

Map [I] [j] = sqrt (city [j]. first-Radar [I]. first) * (city [j]. first-Radar [I]. first)

+ (City [j]. second-Radar [I]. second) * (city [j]. second-Radar [I]. second ));

Ma = max (ma, map [I] [j]);

}

}

 

Void print (double mid)

{

For (int I = 1; I <= n; I ++)

{

For (int j = 1; j <= m; j ++)

If (map [I] [j] <= mid)

{

Printf ("1 ");

}

Else

Printf ("0 ");

Printf ("/n ");

}

}

 

Int main ()

{

Int I, j;

Int T;

Scanf ("% d", & T );

While (T --)

{

// Memset (Size, 0, sizeof (Size)

Scanf ("% d", & n, & m, & count );

For (I = 1; I <= n; I ++)

Scanf ("% lf", & city [I]. first, & city [I]. second );

For (I = 1; I <= m; I ++)

Scanf ("% lf", & Radar [I]. first, & Radar [I]. second );

Double ma = 0;

Init (ma );

Double low = 0, high = ma + 1, mid;

While (low + 1e-8 <= high)

{

Mid = (low + high)/2;

// Mid = 3;

// Printf ("mid = % lf/n", mid );

Makegraph (mid );

// Print (mid );

Bool flag = true;

/* For (I = dia [0]. R; I! = 0; I = dia [I]. R)

If (Size [I] = 0 ){

Flag = false;

Break;

}*/

If (flag & Algorithm_X (0 ))

High = mid;

Else

Low = mid;

}

Printf ("%. 6lf/n", low );

}

Return 0;

}