【POJ】3076 Sudoku

DLX第一题，模板留念。

 /* 3076 */
 #include <iostream>
 #include <string>
 #include <map>
 #include <queue>
 #include <set>
 #include <stack>
 #include <vector>
 #include <deque>
 #include <algorithm>
 #include <cstdio>
 #include <cmath>
 #include <ctime>
 #include <cstring>
 #include <climits>
 #include <cctype>
 #include <cassert>
 #include <functional>
 #include <iterator>
 #include <iomanip>
 using namespace std;
 //#pragma comment(linker,"/STACK:102400000,1024000")

 #define sti                set<int>
 #define stpii            set<pair<int, int> >
 #define mpii            map<int,int>
 #define vi                vector<int>
 #define pii                pair<int,int>
 #define vpii            vector<pair<int,int> >
 #define rep(i, a, n)     for (int i=a;i<n;++i)
 #define per(i, a, n)     for (int i=n-1;i>=a;--i)
 #define clr                clear
 #define pb                 push_back
 #define mp                 make_pair
 #define fir                first
 #define sec                second
 #define all(x)             (x).begin(),(x).end()
 #define SZ(x)             ((int)(x).size())
 #define lson            l, mid, rt<<1
 #define rson            mid+1, r, rt<<1|1

 typedef struct DLX {
     static const int maxc = ** + ;
     static const int maxr = ** + ;
     static const int maxnode = *** + ;
     int n, sz;
     int S[maxc];

     int row[maxnode], col[maxnode];
     int L[maxnode], R[maxnode], U[maxnode], D[maxnode];

     int ansd, ans[maxr];

     void init(int n_)  {
         n = n_;

         for (int i=; i<=n; ++i) {
             L[i] = i - ;
             R[i] = i + ;
             U[i] = i;
             D[i] = i;
         }
         L[] = n;
         R[n] = ;

         sz = n + ;
         memset(S, , sizeof(S));
     }

     void addRow(int r, vi columns) {
         int first = sz;
         int size = SZ(columns);

         for (int i=; i<size; ++i) {
             int c = columns[i];

             L[sz] = sz - ;
             R[sz] = sz + ;

             D[sz] = c;
             U[sz] = U[c];
             D[U[c]] = sz;
             U[c] = sz;

             row[sz] = r;
             col[sz] = c;

             S[c]++;
             sz++;
         }

         R[sz - ] = first;
         L[first] = sz - ;
     }

     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 restore(int c) {
         for (int i=U[c]; i!=c; i=U[i]) {
             for (int j=L[i]; j!=i; j=L[j]) {
                 ++S[col[j]];
                 U[D[j]] = j;
                 D[U[j]] = j;
             }
         }
         L[R[c]] = c;
         R[L[c]] = c;
     }

     bool dfs(int d) {
         if (R[] == ) {
             ansd = d;
             return true;
         }

         int c = R[];
         for (int i=R[]; i!=; 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 (dfs(d+))    return true;
             for (int j=L[i]; j!=i; j=L[j]) {
                 restore(col[j]);
             }
         }
         restore(c);

         return false;
     }

     bool solve(vector<int>& v) {
         v.clr();

         if (!dfs())    return false;

         for (int i=; i<ansd; ++i)
             v.pb(ans[i]);

         return true;
     }
 } DLX;

 DLX solver;
 const int SLOT = ;
 const int ROW = ;
 const int COL = ;
 const int SUB = ;

 int encode(int a, int b, int c) {
     return a*+b*+c+;
 }

 void decode(int code, int& a, int& b, int& c) {
     --code;
     c = code%;
     code /= ;
     b = code%;
     code /= ;
     a = code;
 }

 char puzzle[][];

 bool read() {
     rep(i, , )
         if (scanf("%s", puzzle[i])!=)
             return false;
     return true;
 }

 int main() {
     ios::sync_with_stdio(false);
     #ifndef ONLINE_JUDGE
         freopen("data.in", "r", stdin);
         freopen("data.out", "w", stdout);
     #endif

     int kase = ;

     while (read()) {
         if (kase++)
             putchar('\n');

         solver.init();
         rep(r, , ) {
             rep(c, , ) {
                 rep(v, , ) {
                     if (puzzle[r][c]=='-' || puzzle[r][c]=='A'+v) {
                         vi columns;
                         columns.pb(encode(SLOT, r, c));
                         columns.pb(encode(ROW, r, v));
                         columns.pb(encode(COL, c, v));
                         columns.pb(encode(SUB, r/*+c/, v));
                         solver.addRow(encode(r, c, v), columns);
                     }
                 }
             }
         }

         vi ans;
         bool flag = solver.solve(ans);
         #ifndef ONLINE_JUDGE
             puts(flag ? "Yes":"No");
         #endif
         int sz = SZ(ans);

         rep(i, , sz) {
             int r, c, v;
             decode(ans[i], r, c, v);
             puzzle[r][c] = v + 'A';
         }

         rep(i, , )
             puts(puzzle[i]);
     }

     #ifndef ONLINE_JUDGE
         printf("time = %d.\n", (int)clock());
     #endif

     return ;
 }