来自：http://my.oschina.net/lovewxm/blog/288043?p=1
1 #include <stdio.h>
2 #include <stdlib.h>
3
4 #define BOOL int
5 #define FALSE 1
6 #define TRUE 0
7
8 typedef struct node
9 {
10 int col;
11 int row;
12 int value[10];
13 } Node;
14
15 int findvalue(int sudoku[9][9], Node * node);
16 BOOL general_inspection(int sudoku[9][9]);
17 int blank_num(int sudoku[9][9]);
18 Node * mem_alloc(int num_of_empty);
19 void trace(int sudoku[9][9], Node * node_stack, int num_of_empty);
20 void print_sudoku(int sudoku[9][9]);
21
22
23 int main(void)
24 {
25 int sudoku[9][9] = {{0,0,5,3,0,0,0,0,0},
26 {8,0,0,0,0,0,0,2,0},
27 {0,7,0,0,1,0,5,0,0},
28 {4,0,0,0,0,5,3,0,0},
29 {0,1,0,0,7,0,0,0,6},
30 {0,0,3,2,0,0,0,8,0},
31 {0,6,0,5,0,0,0,0,9},
32 {0,0,4,0,0,0,0,3,0},
33 {0,0,0,0,0,9,7,0,0}
34 };
35
36 int num_of_empty;
37 //为回溯栈分配空间
38 Node * node_stack;
39
40 if(general_inspection(sudoku))
41 {
42 printf("此数独存在错误！请检查\n");
43 print_sudoku(sudoku);
44 return 0;
45 }
46 num_of_empty = blank_num(sudoku);
47 node_stack = mem_alloc(num_of_empty);
48 trace(sudoku, node_stack, num_of_empty);
49 print_sudoku(sudoku);
50
51 return 0;
52 }
53
54 BOOL general_inspection(int sudoku[9][9])
55 {
56 int temp[10] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
57 int i, j, m, n;
58 for(i=0; i<9; i++)
59 for(j=0; j<9; j++)
60 if(sudoku[i][j]!=0)
61 {
62 //检查所在行
63 for(m=0; m<10; m++)
64 temp[m] = 0;
65 for(m=0; m<9; m++)
66 if(sudoku[i][m]!=0)
67 {
68 if(temp[sudoku[i][m]]==0)
69 temp[sudoku[i][m]] = 1;
70 else
71 return FALSE;
72 }
73 //检查所在列
74 for(m=0; m<10; m++)
75 temp[m] = 0;
76 for(m=0; m<9; m++)
77 if(sudoku[m][j]!=0)
78 {
79 if(temp[sudoku[m][j]]==0)
80 temp[sudoku[m][j]] = 1;
81 else
82 return FALSE;
83 }
84 //检查所在九宫格
85 for(m=0; m<10; m++)
86 temp[m] = 0;
87 for(m=0; m<3; m++)
88 for(n=0; n<3; n++)
89 if(sudoku[i/3*3+m][j/3*3+n]!=0)
90 {
91 if(temp[sudoku[i/3*3+m][j/3*3+n]]==0)
92 temp[sudoku[i/3*3+m][j/3*3+n]] = 1;
93 else
94 return FALSE;
95 }
96 }
97 return TRUE;
98 }
99
100 int blank_num(int sudoku[9][9])
101 {
102 //计算所给数独中待填入的空白数
103 int i, j, num = 0;
104 for(i=0; i<9; i++)
105 for(j=0; j<9; j++)
106 if(sudoku[i][j]==0)
107 num++;
108 return num;
109 }
110
111 Node * mem_alloc(int num_of_empty)
112 {
113 Node * node_stack = (Node *)malloc(sizeof(struct node) * num_of_empty);
114 if(node_stack==NULL)
115 {
116 printf("内存分配失败！\n");
117 exit(1);
118 }
119 return node_stack;
120 }
121
122
123 void trace(int sudoku[9][9], Node * node_stack, int num_of_empty)
124 {
125 int i, j, index, k = 0;
126 //回溯法求解数独
127 while(num_of_empty)
128 {
129 for(i=0; i<9; i++)
130 {
131 for(j=0; j<9; j++)
132 {
133 if(sudoku[i][j]==0)
134 {
135 (node_stack + k)->col = i;
136 (node_stack + k)->row = j;
137 sudoku[i][j] = findvalue(sudoku, node_stack+k);
138 if(sudoku[i][j]==-1)
139 {
140 sudoku[i][j] = 0;
141 k--;
142 while((node_stack + k)->value[0]==0)
143 {
144 //当栈空，说明数独错误，无解
145 if(k==0)
146 {
147 printf("此数独无解！\n");
148 //free(node_stack); //为啥这里一释放内存，就弹出debug assertion failed窗口啊！
149 exit(1);
150 }
151 sudoku[(node_stack + k)->col][(node_stack + k)->row] = 0;
152 num_of_empty++;
153 k--;
154 }
155 for(index=1; index<10; index++)
156 if((node_stack + k)->value[index]==0)
157 {
158 sudoku[(node_stack + k)->col][(node_stack + k)->row] = index;
159 (node_stack + k)->value[index] = 1;
160 (node_stack + k)->value[0]--;
161 break;
162 }
163 num_of_empty++;
164 i = (node_stack + k)->col;
165 j = (node_stack + k)->row;
166 }
167 k++;
168 num_of_empty--;
169 }
170 }
171 }
172 }
173 //栈空间使用结束，释放
174 free(node_stack);
175 node_stack=NULL;
176 }
177
178 int findvalue(int sudoku[9][9], Node * node)
179 {
180 int m, n, i = node->col, j = node->row;
181 //初始化栈中存储候选值的数组
182 for(m=0; m<10; m++)
183 node->value[m] = 0;
184 for(m=1; m<10; m++)
185 {
186 node->value[sudoku[i][m-1]] = 1;
187 node->value[sudoku[m-1][j]] = 1;
188 }
189 for(m=0; m<3; m++)
190 for(n=0; n<3; n++)
191 node->value[sudoku[i/3*3+m][j/3*3+n]] = 1;
192
193 //node->value[0]记录候选值个数，前面的循环可能会修改掉它，需要重新赋0值
194 node->value[0] = 0;
195 for(m=1; m<10; m++)
196 if(node->value[m]==0) node->value[0]++;
197 for(m=1; m<10; m++)
198 if(node->value[m]==0)
199 {
200 node->value[m] = 1;
201 node->value[0]--;
202 break;
203 }
204
205 //返回候选值m，若无候选值可用，返回错误标记-1
206 if(m==10)
207 return -1;
208 else
209 return m;
210 }
211
212 void print_sudoku(int sudoku[9][9])
213 {
214 //打印数独
215 int i, j;
216 for(i=0; i<9; i++)
217 {
218 for(j=0; j<9; j++)
219 printf("%2d ", sudoku[i][j]);
220 printf("\n");
221 }
222 }
时间： 2024-10-06 12:35:03