【POJ】2676 Sudoku 
  1 #include<cstdio>
  2 #include<cstring>
  3 #define MAXM 10
  4 #define MAXL 324
  5 #define MAXN 240000
  6 #define INF 0x7FFFFFFF
  7 char sd[MAXM][MAXM];
  8 int L[MAXN], R[MAXN], U[MAXN], D[MAXN], H[MAXN];
  9 int size, C[MAXN], S[MAXN], X[MAXN], Q[MAXN], vis[MAXL * 3];
 10 void Read()
 11 {
 12     int i, j;
 13     for (i = 1; i < MAXM; i++)
 14     {
 15         for (j = 1; j < MAXM; j++)
 16             scanf(" %c", &sd[i][j]);
 17     }
 18 }
 19 void Init()
 20 {
 21     int i;
 22     for (i = 0; i <= MAXL; i++)
 23     {
 24         L[i + 1] = i;
 25         R[i] = i + 1;
 26         U[i] = D[i] = i;
 27         S[i] = 0;
 28     }
 29     R[MAXL] = 0;
 30     size = MAXL + 1;
 31 }
 32 void Remove(int c)
 33 {
 34     int i, j;
 35     L[R[c]] = L[c];
 36     R[L[c]] = R[c];
 37     for (i = D[c]; i != c; i = D[i])
 38     {
 39         for (j = R[i]; j != i; j = R[j])
 40         {
 41             U[D[j]] = U[j];
 42             D[U[j]] = D[j];
 43             S[C[j]]--;
 44         }
 45     }
 46 }
 47 void Resume(int c)
 48 {
 49     int i, j;
 50     L[R[c]] = c;
 51     R[L[c]] = c;
 52     for (i = D[c]; i != c; i = D[i])
 53     {
 54         for (j = R[i]; j != i; j = R[j])
 55         {
 56             U[D[j]] = j;
 57             D[U[j]] = j;
 58             S[C[j]]++;
 59         }
 60     }
 61 }
 62 inline void Link(int r, int c)
 63 {
 64     D[size] = D[c];
 65     U[size] = c;
 66     U[D[c]] = size;
 67     D[c] = size;
 68     if (H[r] < 0)
 69         H[r] = L[size] = R[size] = size;
 70     else
 71     {
 72         L[size] = H[r];
 73         R[size] = R[H[r]];
 74         L[R[H[r]]] = size;
 75         R[H[r]] = size;
 76     }
 77     S[c]++;
 78     X[size] = r;
 79     C[size++] = c;
 80 }
 81 bool Dance(int now)
 82 {
 83     int i, j, c, temp;
 84     if (R[0] == 0)
 85         return true;
 86     for (temp = INF,i = R[0]; i; i = R[i])
 87     {
 88         if (S[i] < temp)
 89         {
 90             temp = S[i];
 91             c = i;
 92         }
 93     }
 94     Remove(c);
 95     for (i = D[c]; i != c; i = D[i])
 96     {
 97         vis[X[i]] = true;
 98         for (j = R[i]; j != i; j = R[j])
 99             Remove(C[j]);
100         if (Dance(now + 1))
101             return true;
102         for (j = L[i]; j != i; j = L[j])
103             Resume(C[j]);
104         vis[X[i]] = false;
105     }
106     Resume(c);
107     return false;
108 }
109 int main()
110 {
111     int i, j, k, r, ca;
112     scanf("%d", &ca);
113     while (ca--)
114     {
115         Read();
116         Init();
117         for (r = 0, i = 1; i < MAXM; i++)
118         {
119             for (j = 1; j < MAXM; j++)
120             {
121                 if (sd[i][j] == '0')
122                 {
123                     for (k = 1; k < MAXM; k++)
124                     {
125                         H[++r] = -1;
126                         Q[r] = k;
127                         Link(r, (i - 1) * 9 + k);
128                         Link(r, 81 + (j - 1) * 9 + k);
129                         Link(r, 162 + ((i - 1) / 3 * 3 + (j - 1) / 3) * 9 + k);
130                         Link(r, 243 + (i - 1) * 9 + j);
131                     }
132                 }
133                 else
134                 {
135                     H[++r] = -1;
136                     k = sd[i][j] - '0';
137                     Q[r] = k;
138                     Link(r, (i - 1) * 9 + k);
139                     Link(r, 81 + (j - 1) * 9 + k);
140                     Link(r, 162 + ((i - 1) / 3 * 3 + (j - 1) / 3) * 9 + k);
141                     Link(r, 243 + (i - 1) * 9 + j);
142                 }
143             }
144         }
145         memset(vis, false, sizeof(vis));
146         Dance(0);
147         for (k = 0, i = 1; i <= r; i++)
148         {
149             if (vis[i])
150             {
151                 k++;
152                 printf("%d", Q[i]);
153                 if (k % 9 == 0)
154                     putchar('\n');
155             }
156         }
157     }
158     return 0;
159 }
posted on 2012-07-24 20:17  DrunBee  阅读(175)  评论(0)  编辑  收藏  举报