题意很明确，让你解一个9*9的数独。
DFS即可。
#include <cstdio> #include <cstring> #include <iostream> #include <algorithm> #include <functional> using namespace std; #define REP(i,n) for(int i(0); i < (n); ++i) #define rep(i,a,b) for(int i(a); i <= (b); ++i) #define dec(i,a,b) for(int i(a); i >= (b); --i) #define for_edge(i,x) for(int i = H[x]; i; i = X[i]) #define LL long long #define ULL unsigned long long #define MP make_pair #define PB push_back #define FI first #define SE second #define INF 1 << 30 const int N = 100000 + 10; const int M = 10000 + 10; const int Q = 1000 + 10; const int A = 30 + 1; struct node{ int x, y; } d[Q]; char ch; bool a[A][A]; int f[A][A], r[A][A], c[A][A], v[A][A]; bool rr[A][A], cc[A][A], vv[A][A]; int num; inline void print(){ rep(i, 1, 9){rep(j, 1, 8) printf("%d ", f[i][j]); printf("%d", f[i][9]); putchar(10);} } void dfs(int now){ if (now > num){ print(); return ;} int x = d[now].x, y = d[now].y; rep(i, 1, 9){ if (vv[v[x][y]][i]) continue; if (cc[c[x][y]][i]) continue; if (rr[r[x][y]][i]) continue; f[x][y] = i; vv[v[x][y]][i] = true; cc[c[x][y]][i] = true; rr[r[x][y]][i] = true; dfs(now + 1); f[x][y] = 0; vv[v[x][y]][i] = false; cc[c[x][y]][i] = false; rr[r[x][y]][i] = false; } } int main(){ #ifndef ONLINE_JUDGE freopen("test.txt", "r", stdin); freopen("test.out", "w", stdout); #endif rep(i, 1, 3) rep(j, 1, 3) v[i][j] = 1; rep(i, 1, 3) rep(j, 4, 6) v[i][j] = 2; rep(i, 1, 3) rep(j, 7, 9) v[i][j] = 3; rep(i, 4, 6) rep(j, 1, 3) v[i][j] = 4; rep(i, 4, 6) rep(j, 4, 6) v[i][j] = 5; rep(i, 4, 6) rep(j, 7, 9) v[i][j] = 6; rep(i, 7, 9) rep(j, 1, 3) v[i][j] = 7; rep(i, 7, 9) rep(j, 4, 6) v[i][j] = 8; rep(i, 7, 9) rep(j, 7, 9) v[i][j] = 9; rep(i, 1, 9) rep(j, 1, 9) r[i][j] = i, c[i][j] = j; int Case = 0; //rep(i, 1, 9){rep(j, 1, 9) printf("%d ", c[i][j]); putchar(10); } while (~scanf("%c ", &ch)){ if (Case) puts(""); else Case = 1; // memset(a, false, sizeof a); memset(f, 0, sizeof f); memset(cc, false, sizeof cc); memset(vv, false, sizeof vv); memset(rr, false, sizeof vv); memset(d, 0, sizeof d); num = 0; if (ch == '?'){ f[1][1] = 0; d[++num].x = 1, d[num].y = 1; } else{ int np = (int)ch - 48; f[1][1] = np; cc[c[1][1]][np] = true; vv[v[1][1]][np] = true; rr[r[1][1]][np] = true; } rep(cnt, 2, 81){ scanf("%c ", &ch); int x = (cnt - 1) / 9 + 1, y = (cnt - 1) % 9 + 1; if (ch == '?'){ f[x][y] = 0; d[++num].x = x, d[num].y = y; } else{ int np = (int)ch - 48; f[x][y] = np; cc[c[x][y]][np] = true; vv[v[x][y]][np] = true; rr[r[x][y]][np] = true; } //rep(i, 1, 9){rep(j, 1, 9) printf("%d ", f[i][j]); putchar(10);} } dfs(1); } return 0; }