poj-2676sudoku

思路：深搜， 主要是判断是否在同一行，同一列，同一格。

#include<iostream>#include<cstdio>#include<cstring>#include<algorithm>using namespace std;const int maxn=10;const int INF=0x3f3f3f3f;int T, cnt;int mp[maxn][maxn], row[maxn][maxn], col[maxn][maxn], grid[maxn][maxn];int zero[maxn*maxn][2];int location(int i, int j){return ((i-1)/3)*3+(j-1)/3+1;}int dfs(int step){if(step==cnt+1)return 1;for(int i=1; i<=9; i++){if(!row[zero[step][0]][i] && !col[zero[step][1]][i] && !grid[location(zero[step][0], zero[step][1])][i]){row[zero[step][0]][i]=1;col[zero[step][1]][i]=1;grid[location(zero[step][0], zero[step][1])][i]=1;mp[zero[step][0]][zero[step][1]]=i;if(dfs(step+1))return 1;row[zero[step][0]][i]=0;col[zero[step][1]][i]=0;grid[location(zero[step][0], zero[step][1])][i]=0;}}return 0;}int main(){cin>>T;while(T--){cnt=0;memset(col, 0, sizeof(col));memset(row, 0, sizeof(row));memset(grid, 0, sizeof(grid));for(int i=1; i<=9; i++){for(int j=1; j<=9; j++){scanf("%1d", &mp[i][j]);if(mp[i][j]){row[i][mp[i][j]]=1;col[j][mp[i][j]]=1;grid[location(i, j)][mp[i][j]]=1;}else{zero[++cnt][0]=i;zero[cnt][1]=j;}}}dfs(1);for(int i=1; i<=9; i++){for(int j=1; j<=9; j++)cout<<mp[i][j];cout<<endl;}}return 0;}