P7351 “MCOI-04” Dream SMP
Background
**This is an output-only problem.**
Link: https://pan.baidu.com/s/1D3ytb0626EKZ_emw3gLwVQ
Extraction code: inbj
Description
Dream SMP can be seen as $n$ regions numbered $0,1,\dots,n-1$.
Dream wants to divide these $n$ regions into $8$ countries numbered $0,1,\dots,7$. Each region belongs to exactly one country, but a country may contain no regions.
The regions give $m$ sets of constraints on the partition plan. The $i$-th constraint is represented by four parameters $(u_i,a_i,v_i,b_i)$. A partition plan is valid if and only if for every constraint, region $u_i$ does not belong to country $a_i$ **or** region $v_i$ does not belong to country $b_i$. Here **or** is logical OR.
Dream guarantees that there is at least one valid partition plan. You need to construct a valid partition plan.
Input Format
The first line contains two positive integers $n$ and $m$.
The next $m$ lines each contain four positive integers $u_i,a_i,v_i,b_i$.
Output Format
Output a string of length $n$.
The $i$-th character of the string is the country that region $i$ belongs to.
Explanation/Hint
#### Sample 1 Explanation
23322, 23332, and 23333 are all valid plans.
#### Constraints
For $100\%$ of the data, $1 \le n \le 10^5$, $1 \le m \le 10^6$.
For specific properties, please refer to the input testdata yourself.
[Click here to download the input data.](https://gitee.com/w33z8kqrqk8zzzx33/dream-oi-extra/raw/master/down.zip)
If the download link above does not work, see this one below:
Link: https://pan.baidu.com/s/1D3ytb0626EKZ_emw3gLwVQ
Extraction code: inbj
#### Notes
[Minecraft OI Round 4](https://www.luogu.com.cn/contest/33344) Extra
Idea & solution: w33z8kqrqk8zzzx33. Check: tiger2005.
Translated by ChatGPT 5