Dancing Links x
2014-07-27 16:25
211 查看
参考资料:
模板代码抄的网上大神的:博客地址
看了一篇大神的论文:《Dancing Links 在搜索中的应用》
学习的过程前面精确覆盖的时候还好,后面重复覆盖的时候基本懵掉了……当时也没看到大神的博客论文里没模板,我对A*和IDA*一点都不了解。到现在也没怎么看明白,就大概弄明白了点模板怎么用。
第一类问题:精确覆盖
从矩阵中找到一些行,使每一列最多有一个1。
第二类问题:重复覆盖
从矩阵中找到一些行,使每一列至少有一个1。
精确覆盖:
重复覆盖:
模板代码抄的网上大神的:博客地址
看了一篇大神的论文:《Dancing Links 在搜索中的应用》
学习的过程前面精确覆盖的时候还好,后面重复覆盖的时候基本懵掉了……当时也没看到大神的博客论文里没模板,我对A*和IDA*一点都不了解。到现在也没怎么看明白,就大概弄明白了点模板怎么用。
第一类问题:精确覆盖
从矩阵中找到一些行,使每一列最多有一个1。
第二类问题:重复覆盖
从矩阵中找到一些行,使每一列至少有一个1。
精确覆盖:
const int maxnode = 100010; const int MaxM = 1010; const int MaxN = 1010; struct DLX { int n,m,size; int U[maxnode],D[maxnode],R[maxnode],L[maxnode],Row[maxnode],Col[maxnode]; int H[MaxN], S[MaxM]; int ansd, ans[MaxN]; void init(int _n,int _m) { n = _n; m = _m; for(int i = 0;i <= m;i++) { S[i] = 0; U[i] = D[i] = i; L[i] = i-1; R[i] = i+1; } R[m] = 0; L[0] = m; size = m; for(int i = 1;i <= n;i++) H[i] = -1; } void Link(int r,int c) { ++S[Col[++size]=c]; Row[size] = r; D[size] = D[c]; U[D[c]] = size; U[size] = c; D[c] = size; if(H[r] < 0)H[r] = L[size] = R[size] = size; else { R[size] = R[H[r]]; L[R[H[r]]] = size; L[size] = H[r]; R[H[r]] = size; } } void remove(int c) { L[R[c]] = L[c]; R[L[c]] = R[c]; for(int i = D[c];i != c;i = D[i]) for(int j = R[i];j != i;j = R[j]) { U[D[j]] = U[j]; D[U[j]] = D[j]; --S[Col[j]]; } } void resume(int c) { for(int i = U[c];i != c;i = U[i]) for(int j = L[i];j != i;j = L[j]) ++S[Col[U[D[j]]=D[U[j]]=j]]; L[R[c]] = R[L[c]] = c; } //d为递归深度 bool Dance(int d) { if(R[0] == 0) { ansd = d; return true; } int c = R[0]; for(int i = R[0];i != 0;i = R[i]) if(S[i] < S[c]) c = i; remove(c); for(int i = D[c];i != c;i = D[i]) { ans[d] = Row[i]; for(int j = R[i]; j != i;j = R[j])remove(Col[j]); if(Dance(d+1))return true; for(int j = L[i]; j != i;j = L[j])resume(Col[j]); } resume(c); return false; } };
重复覆盖:
const int maxnode = 3000; const int MaxM = 55; const int MaxN = 55; int K; struct DLX { int n,m,size; int U[maxnode],D[maxnode],R[maxnode],L[maxnode],Row[maxnode],Col[maxnode]; int H[MaxN],S[MaxN]; int ands,ans[MaxN]; void init(int _n,int _m) { n = _n; m = _m; for(int i = 0;i <= m;i++) { S[i] = 0; U[i] = D[i] = i; L[i] = i-1; R[i] = i+1; } R[m] = 0; L[0] = m; size = m; for(int i = 1;i <= n;i++) H[i] = -1; } void Link(int r,int c) { ++S[Col[++size]=c]; Row[size] = r; D[size] = D[c]; U[D[c]] = size; U[size] = c; D[c] = size; if(H[r] < 0)H[r] = L[size] = R[size] = size; else { R[size] = R[H[r]]; L[R[H[r]]] = size; L[size] = H[r]; R[H[r]] = size; } } void remove(int c) { for(int i = D[c];i != c;i = D[i]) L[R[i]] = L[i], R[L[i]] = R[i]; } void resume(int c) { for(int i = U[c];i != c;i = U[i]) L[R[i]]=R[L[i]]=i; } bool v[maxnode]; int f() { int ret = 0; for(int c = R[0];c != 0;c = R[c])v[c] = true; for(int c = R[0];c != 0;c = R[c]) if(v[c]) { ret++; v[c] = false; for(int i = D[c];i != c;i = D[i]) for(int j = R[i];j != i;j = R[j]) v[Col[j]] = false; } return ret; } bool Dance(int d) { if(d + f() > K)return false; if(R[0] == 0)return d <= K; int c = R[0]; for(int i = R[0];i != 0;i = R[i]) if(S[i] < S[c]) c = i; for(int i = D[c];i != c;i = D[i]) { remove(i); for(int j = R[i];j != i;j = R[j])remove(j); if(Dance(d+1))return true; for(int j = L[i];j != i;j = L[j])resume(j); resume(i); } return false; } };
相关文章推荐
- dancing links 算法 解 Sudoku
- 搜索链表优化(dancing links?)
- HUST1017--Exact cover(Dancing Links)
- Dancing Links and Exact Cover
- poj 3076 Sudoku //Dancing Links
- zoj 3209 Dancing links/hust 1017
- Dancing Links & Algorithm X
- HDU 3663 Power Stations(Dancing_Links精确覆盖)
- Dancing Links - nuclear weapon for Exact Cover problems
- DLX Dancing Links X Algorithm 舞蹈链 学习总结
- HDU 2295 Radar (二分 + Dancing Links 重复覆盖模型 )
- ZOJ 3209 Treasure Map dancing links
- DLX舞蹈链(Dancing Links)——求解精确覆盖问题
- HDU 2295 Radar dancing links 重复覆盖
- Poj DancingLinks(3372 3074 3076)
- Dancing Links + A* 应用于精确覆盖、重复覆盖
- hdu4979 A simple math problem.Dancing Links,打表
- HDU 3335 Divisibility dancing links 重复覆盖
- ZOJ 3209 Treasure Map (Dancing Links)
- Dancing Links hdoj 5046 3656 2295