搜索。。。还要A*。。。不会呢。。。
Orz 这个blog吧：iwtwiioi
1 /************************************************************** 2 Problem: 1085 3 User: rausen 4 Language: C++ 5 Result: Accepted 6 Time:876 ms 7 Memory:804 kb 8 ****************************************************************/ 9 10 #include <cstdio> 11 #include <algorithm> 12 13 using namespace std; 14 const int dx[8] = {1, 2, 2, 1, -1, -2, -2, -1}; 15 const int dy[8] = {2, 1, -1, -2, -2, -1, 1, 2}; 16 const int last[6][6] = { 17 {0, 0, 0, 0, 0, 0}, 18 {0, 1, 1, 1, 1, 1}, 19 {0, 0, 1, 1, 1, 1}, 20 {0, 0, 0, 2, 1, 1}, 21 {0, 0, 0, 0, 0, 1}, 22 {0, 0, 0, 0, 0, 0}}; 23 24 int s[6][6], ans, have_ans, X, Y; 25 26 inline bool check(){ 27 int i, j; 28 for (i = 1; i <= 5; ++i) 29 for (j = 1; j <= 5; ++j) 30 if (s[i][j] != last[i][j]) return 0; 31 return 1; 32 } 33 34 inline bool f(const int &g){ 35 int h = 0, i, j; 36 for (i = 1; i <= 5; ++i) 37 for (j = 1; j <= 5; ++j) 38 if (s[i][j] != last[i][j] && (++h) + g > ans) return 0; 39 return 1; 40 } 41 42 void dfs(const int &x, const int &y, const int &g){ 43 if (g == ans){ 44 if (check()) have_ans = 1; 45 return; 46 } 47 if (have_ans) return; 48 int i, X, Y; 49 for (i = 0; i < 8; ++i){ 50 X = x + dx[i], Y = y + dy[i]; 51 if (X < 1 || Y < 1 || X > 5 || Y > 5) continue; 52 swap(s[x][y], s[X][Y]); 53 if (f(g)) dfs(X, Y, g + 1); 54 swap(s[x][y], s[X][Y]); 55 } 56 } 57 58 int main(){ 59 int T, i, j; 60 scanf("%d", &T); 61 char ch; 62 while (T--){ 63 for (i = 1; i <= 5; ++i) 64 for (j = 1; j <= 5; ++j){ 65 ch = getchar(); 66 while (ch != '*' && ch != '0' && ch != '1') 67 ch = getchar(); 68 if (ch == '*') 69 s[i][j] = 2, X = i, Y = j; 70 else s[i][j] = ch - '0'; 71 } 72 if (check()){ 73 printf("0 "); 74 continue; 75 } 76 have_ans = 0; 77 for (ans = 1; ans <= 15; ++ans){ 78 dfs(X, Y, 0); 79 if (have_ans) break; 80 } 81 if (have_ans) printf("%d ", ans); 82 else printf("-1 "); 83 } 84 return 0; 85 }