这是昨天周赛的题,我竟然不会怎么判断多解,后来一google,卧槽,我想复杂了。。。。。。直接看能搜出来几次就行了。
这题就是个变形,先floodfill一下,然后就是模板了
然后发现比大华的快了好几倍,然后加了输入挂后,瞬间成Best solution中的rank1了
/* ID: sdj22251 PROG: inflate LANG: C++ */ #include <iostream> #include <vector> #include <list> #include <map> #include <set> #include <deque> #include <queue> #include <stack> #include <bitset> #include <algorithm> #include <functional> #include <numeric> #include <utility> #include <sstream> #include <iomanip> #include <cstdio> #include <cmath> #include <cstdlib> #include <cctype> #include <string> #include <cstring> #include <cmath> #include <ctime> #define MAXN 9*9*9*9 #define INF 1000000000 #define N 9 #define M 9*9*9+5 using namespace std; int L[MAXN], R[MAXN], C[MAXN], S[M], U[MAXN], D[MAXN], H[M], O[M], X[MAXN]; //X用来存储行,C用来存储列,H用来存储每行中的第一个结点,O用来存储结果 int cnt, head; char mp[N + 5][N + 5], ans[N * N + 5]; bool vis[N * N * 4 + 5]; int ditu[N + 5][N + 5], pos[N * 5][N * 5]; int num, ct; void link(int r, int c) { S[c]++; C[cnt] = c; X[cnt] = r; U[cnt] = c; D[cnt] = D[c]; U[D[c]] = cnt; D[c] = cnt; if(H[r] == -1) { H[r] = cnt; L[cnt] = R[cnt] = cnt; } else { L[cnt] = H[r]; R[cnt] = R[H[r]]; L[R[H[r]]] = cnt; R[H[r]] = cnt; } cnt++; } void init() { cnt = 0; head = 0; num = 0; ct = 0; for(int i = 0; i <= N * N * 4; i++) { S[i] = 0; vis[i] = 0; D[i] = U[i] = i; R[i] = (i + 1) % (N * N * 4 + 1); L[i] = (i + N * N * 4) % (N * N * 4 + 1); cnt++; } memset(H, -1, sizeof(H)); } void cal(int &r, int &cx, int &cy, int &ck, int &cg, int i, int j, int k) { r = (i * N + j) * N + k - 1; //代表所属的行 cg = i * N + j + 1; //代表的是数独中i,j位置所属的列 cx = N * N + i * N + k; //代表数独中同一行所属的列 cy = N * N * 2 + j * N + k; //代表数独中同一列所属的列 ck = N * N * 3 + (pos[i][j] - 1) * N + k;//代表数独中同一宫所属的列 } void search(int x, int y) { pos[x][y] = ct; int ta = ditu[x][y]; if(ta & 16) ta ^= 16; if(ta & 32) ta ^= 32; if(ta & 64) ta ^= 64; if(ta & 128) ta ^= 128; mp[x][y] = ta + '0'; ta = ditu[x][y]; if((ta & 16) == 0 && x >= 1 && pos[x - 1][y] == 0) search(x - 1, y); if((ta & 32) == 0 && y < N - 1 && pos[x][y + 1] == 0) search(x, y + 1); if((ta & 64) == 0 && x < N - 1 && pos[x + 1][y] == 0) search(x + 1, y); if((ta & 128) == 0 && y >= 1 && pos[x][y - 1] == 0) search(x, y - 1); } void readdata() { int r, cx, cy, ck, cg; memset(pos, 0, sizeof(pos)); for(int i = 0; i < N; i++) for(int j = 0; j < N; j++) scanf("%d", &ditu[i][j]); for(int i = 0; i < N; i++) for(int j = 0; j < N; j++) if(pos[i][j] == 0) { ++ct; search(i, j); } for(int i = 0; i < N; i++) for(int j = 0; j < N; j++) if(mp[i][j] != '0') { cal(r, cx, cy, ck, cg, i, j, mp[i][j] - '0'); link(r, cx); link(r, cy); link(r, ck); link(r, cg); vis[cx] = vis[cy] = vis[ck] = vis[cg] = 1; } for(int i = 0; i < N; i++) for(int j = 0; j < N; j++) for(int k = 1; k <= N; k++) { cal(r, cx, cy, ck, cg, i, j, k); if(vis[cx] || vis[cy] || vis[ck] || vis[cg]) continue; link(r, cx); link(r, cy); link(r, ck); link(r, cg); } } void removes(int c) { L[R[c]] = L[c]; R[L[c]] = R[c]; for(int i = D[c]; i != c; i = D[i]) for(int j = R[i]; j != i; j = R[j]) { U[D[j]] = U[j]; D[U[j]] = D[j]; S[C[j]]--; } } void resumes(int c) { for(int i = U[c]; i != c; i = U[i]) for(int j = L[i]; j != i; j = L[j]) { U[D[j]] = j; D[U[j]] = j; S[C[j]]++; } L[R[c]] = c; R[L[c]] = c; } bool dfs(int k) { if(R[head] == head) { num++; //直接用num记录有多少个解 for(int i = 0; i < k; i++) ans[X[O[i]] / N] = X[O[i]] % 9 + '1'; if(num >= 2) return true; else return false; } int s = INF, c; for(int i = R[head]; i != head; i = R[i]) if(s > S[i]) { s = S[i]; c = i; } removes(c); for(int i = U[c]; i != c; i = U[i]) { O[k] = i; for(int j = R[i]; j != i; j = R[j]) removes(C[j]); if(dfs(k + 1)) return true; for(int j = L[i]; j != i; j = L[j]) resumes(C[j]); } resumes(c); return false; } int main() { int T, cas = 0; scanf("%d", &T); while(T--) { init(); readdata(); dfs(0); printf("Case %d:\n", ++cas); if(num == 0) printf("No solution\n"); else if(num == 1) { for(int i = 0; i < N * N; i++) { printf("%c", ans[i]); if((i + 1) % N == 0) printf("\n"); } } else printf("Multiple Solutions\n"); } return 0; }