八皇后問題

• Green Judge b039
• 思路：DFS

int ans[12];
int N;

void dfs(int row){
    if(row == N){
        for(int i = 0; i < N; ++i)cout << ans[i] << ' ';
        cout << endl;
    }else{
        for(int i = 0; i < N; ++i){
            ans[row] = i+1;
            bool good = 1;//檢查第i格能否擺放
            for(int j = 0; j < row && good; ++j){
                if(ans[j] == ans[row])good = false;//正上方＆正下方
                if(ans[j]-ans[row] == j-row)good = false;//左上方＆右下方
                if(ans[j]-ans[row] == -j+row)good = false;//右上方＆左下方
            }
            if(!good)continue;
            dfs(row+1);
        }
    }
}