1 #include <iostream>
2 #include <stdio.h>
3 #include <string.h>
4
5 using namespace std;
6
7 char g[90];
8
9 bool isPlace(int n)
10 {
11 for (int i = 0; i < 9; i++) {
12 int nn = n / 9 * 9 + i;
13 if (g[nn] == g[n] && nn != n) return false;
14 nn = n % 9 + i * 9;
15 if (g[nn] == g[n] && nn != n) return false;
16 nn = (n / 27 * 3 + i / 3) * 9 + n % 9 / 3 * 3 + i % 3;
17 if (g[nn] == g[n] && nn != n) return false;
18 }
19 return true;
20 }
21
22 void dfs(int n)
23 {
24 if (n == 81) {
25 puts(g);
26 return;
27 }
28 if (g[n] == '.') {
29 for (int i = 1; i <= 9; i++) {
30 g[n] = i + '0';
31 if (isPlace(n)) {
32 dfs(n + 1);
33 }
34 }
35 g[n] = '.';
36 }
37 else
38 dfs(n + 1);
39 }
40
41 int main()
42 {
43 while (scanf("%s", g) == 1) {
44 if (strcmp(g, "end") == 0) break;
45 dfs(0);
46 }
47 return 0;
48 }
输入：
.2738..1..1...6735.......293.5692.8...........6.1745.364.......9518...7..8..6534.
......52..8.4......3...9...5.1...6..2..7........3.....6...1..........7.4.......3.
end
输出：
527389416819426735436751829375692184194538267268174593643217958951843672782965341
416837529982465371735129468571298643293746185864351297647913852359682714128574936
Time Limit:1000MS。虽然超时了，但是我觉得能解出来就已经非常棒了（因为代码非常漂亮）！超时原因在于回溯的时候出栈的用时，我会改进的。