DLX精确覆盖 hdu4069 Squiggly Sudoku

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题意：将9*9的棋盘分割成了9个部分，每个部分都是9个格子，然后现在要求每个部分的数字恰是1~9的排列，每一行每一列恰是1~9的排列，问是否有解，有多少组解，如果只有1组解打印出来

思路：先通过DFS求出所在的部分，然后剩下的和DLX精确覆盖求数独就是一样的了

#include<map>#include<set>#include<cmath>#include<stack>#include<queue>#include<cstdio>#include<cctype>#include<string>#include<vector>#include<cstring>#include<iostream>#include<algorithm>#include<functional>#define fuck printf("fuck")#define FIN freopen("input.txt","r",stdin)#define FOUT freopen("output.txt","w+",stdout)using namespace std;typedef long long LL;const int MS = 10 + 5;const int MX = 1000 + 5;const int MN = 300000 + 5;const int INF = 0x3f3f3f3f;int vis[3][MS][MS], Z[MS][MS], r;int A[MS][MS], W[MS][MS], pre[MS][MS];struct DLX {    int m, n;    int H[MX], S[MX], ans;    int Row[MN], Col[MN], rear;    int L[MN], R[MN], U[MN], D[MN];    void Init(int _m, int _n) {        m = _m; n = _n;        rear = n; ans = 0;        for(int i = 0; i <= n; i++) {            S[i] = 0;            L[i] = i - 1;            R[i] = i + 1;            U[i] = D[i] = i;        }        L[0] = n; R[n] = 0;        for(int i = 1; i <= m; i++) {            H[i] = -1;        }    }    void Link(int r, int c) {        int rt = ++rear;        Row[rt] = r; Col[rt] = c; S[c]++;        D[rt] = D[c]; U[D[c]] = rt;        U[rt] = c; D[c] = rt;        if(H[r] == -1) {            H[r] = L[rt] = R[rt] = rt;        } else {            int id = H[r];            R[rt] = R[id]; L[R[id]] = rt;            L[rt] = id; R[id] = rt;        }    }    void Remove(int c) {        R[L[c]] = R[c]; L[R[c]] = L[c];        for(int i = D[c]; i != c; i = D[i]) {            for(int j = R[i]; j != i; j = R[j]) {                D[U[j]] = D[j]; U[D[j]] = U[j];                S[Col[j]]--;            }        }    }    void Resume(int c) {        for(int i = U[c]; i != c; i = U[i]) {            for(int j = L[i]; j != i; j = L[j]) {                D[U[j]] = U[D[j]] = j;                S[Col[j]]++;            }        }        R[L[c]] = L[R[c]] = c;    }    bool Dance(int cnt) {        if(R[0] == 0) {            for(int i = 1; i <= 9; i++) {                for(int j = 1; j <= 9; j++) {                    if(pre[i][j]) W[i][j] = pre[i][j];                }            }            ans++;            if(ans >= 2) return true;            return false;        }        int c = R[0];        for(int i = R[0]; i != 0; i = R[i]) {            if(S[i] < S[c]) c = i;        }        Remove(c);        for(int i = D[c]; i != c; i = D[i]) {            for(int j = R[i]; j != i; j = R[j]) Remove(Col[j]);            int r = Row[i];            pre[(r - 1) / 81 + 1][((r - 1) % 81) / 9 + 1] = ((r - 1) % 81) % 9 + 1;            if(Dance(cnt + 1)) return true;            for(int j = L[i]; j != i; j = L[j]) Resume(Col[j]);        }        Resume(c);        return false;    }} G;void Link(int x, int y, int z, int k) {    int id = ((x - 1) * 9 + y - 1) * 9 + k;    G.Link(id, (x - 1) * 9 + y);    G.Link(id, 9 * 9 + (x - 1) * 9 + k);    G.Link(id, 2 * 9 * 9 + (y - 1) * 9 + k);    G.Link(id, 3 * 9 * 9 + (z - 1) * 9 + k);}void DFS(int x, int y, int id) {    int w = A[x][y];    Z[x][y] = id;    if(w >= 128) w -= 128;    else if(y - 1 >= 1 && !Z[x][y - 1]) DFS(x, y - 1, id);    if(w >= 64) w -= 64;    else if(x + 1 <= 9 && !Z[x + 1][y]) DFS(x + 1, y, id);    if(w >= 32) w -= 32;    else if(y + 1 <= 9 && !Z[x][y + 1]) DFS(x, y + 1, id);    if(w >= 16) w -= 16;    else if(x - 1 >= 1 && !Z[x - 1][y]) DFS(x - 1, y, id);    W[x][y] = w;    vis[0][x][w] = vis[1][y][w] = vis[2][id][w] = 1;}int main() {    int T, ansk = 0; //FIN;    scanf("%d", &T);    while(T--) {        r = 0;        memset(Z, 0, sizeof(Z));        memset(pre, 0, sizeof(pre));        memset(vis, 0, sizeof(vis));        G.Init(9 * 9 * 9, 4 * 9 * 9);        for(int i = 1; i <= 9; i++) {            for(int j = 1; j <= 9; j++) {                scanf("%d", &A[i][j]);            }        }        for(int i = 1; i <= 9; i++) {            for(int j = 1; j <= 9; j++) {                if(!Z[i][j]) DFS(i, j, ++r);            }        }        for(int i = 1; i <= 9; i++) {            for(int j = 1; j <= 9; j++) {                if(W[i][j]) Link(i, j, Z[i][j], W[i][j]);                else for(int k = 1; k <= 9; k++) {                        int z = Z[i][j];                        if(!vis[0][i][k] && !vis[1][j][k] && !vis[2][z][k]) {                            Link(i, j, z, k);                        }                    }            }        }        G.Dance(0);        printf("Case %d:\n", ++ansk);        if(G.ans == 0) printf("No solution\n");        else if(G.ans == 2) printf("Multiple Solutions\n");        else for(int i = 1; i <= 9; i++) {                for(int j = 1; j <= 9; j++) {                    printf("%d", W[i][j]);                }                printf("\n");            }    }    return 0;}

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