hdu 1426 Sudoku Killer(DFS)

 1 #include <iostream>
 2 #include <memory.h>
 3 #include <vector>
 4 #include <string>
 5 #include <cstdio>
 6 using namespace std;
 7 
 8 int row[11][11],col[11][11],blo[11][11],mp[11][11];
 9 struct node{
10     int x,y;
11 };
12 node unknow[111];
13 int cnt;
14 
15 
16 void show_result()
17 {
18     for (int i = 0; i < 9; ++ i) {
19         for (int j = 0;j < 9; ++ j) {
20             cout << mp[i][j] ;
21             if (j == 8) puts("");
22             else cout << " ";
23         }
24     }
25 }
26 
27 int dfs(int now)
28 {
29     if (now == cnt) return 1;
30     int xx, yy;
31     xx = unknow[now].x;
32     yy = unknow[now].y;
33     int block = (xx/3)*3 + yy/3;
34     for (int i = 1;i <= 9; ++ i) {
35         if (row[xx][i] == 0 && col[yy][i] == 0 && blo[block][i] == 0) {
36             mp[xx][yy] = i;
37             row[xx][i] = 1;
38             col[yy][i] = 1;
39             blo[block][i] = 1;
40             if (dfs(now + 1)) return 1;
41             row[xx][i] = 0;
42             col[yy][i] = 0;
43             blo[block][i] = 0;
44         }
45     }
46     return 0;
47 }
48 
49 void init()
50 {
51 
52     memset(row,0,sizeof(row));
53     memset(col,0,sizeof(col));
54     memset(blo,0,sizeof(blo));
55     cnt = 0;
56 }
57 
58 
59 int main()
60 {
61     char temp[30];
62     int ok = 1;
63     while (cin >> temp) {
64         if (ok) ok = 0;
65         else cout << endl;
66         init();
67         if (temp[0] == ‘?‘)
68         {
69             unknow[cnt].x = 0;
70             unknow[cnt++].y = 0;
71         }
72         else  {
73             mp[0][0] = temp[0] - ‘0‘;
74             row[0][mp[0][0]] = 1;
75             col[0][mp[0][0]] = 1;
76             blo[0][mp[0][0]] = 1;
77         }
78 
79         for (int i = 0;i < 9; ++ i)
80             for (int j = 0;j < 9; ++ j) {
81                 if (i == 0 && j == 0) continue;
82                 cin >> temp[0];
83                 if (temp[0] == ‘?‘) {
84                     unknow[cnt].x = i;
85                     unknow[cnt++].y = j;
86                 }
87                 else  {
88                     mp[i][j] = temp[0] - ‘0‘;
89                     row[i][mp[i][j]] = 1;
90                     col[j][mp[i][j]] = 1;
91                     blo[(i/3)*3 + j/3][mp[i][j]] = 1;
92                 }
93             }
94         dfs(0);
95         show_result();
96     }
97     return 0;
98 }