Submission #1205737

#	Time	Username	Problem	Language	Result	Execution time	Memory
1205737		12345678	KOVANICE (COI15_kovanice)	C++20	100 / 100	122 ms	36920 KiB

kovanice

#include <bits/stdc++.h>

using namespace std;

const int nx=3e5+5;

int n, m, k, dsu[nx], degdn[nx], degup[nx], u, v, lvlup[nx], lvldn[nx], res[nx];
char opr;
string s;
vector<int> dn[nx], up[nx];
vector<pair<int, int>> edg;
queue<int> q;

int find(int x)
{
    if (dsu[x]==x) return x;
    return dsu[x]=find(dsu[x]);
}

int tonum(string &x)
{
    int res=0, sz=x.size();
    for (int i=0; i<sz; i++) res*=10, res+=x[i]-'0';
    return res;
}

int main()
{
    cin.tie(NULL)->sync_with_stdio(false);
    cin>>n>>m>>k;
    for (int i=1; i<=m; i++) dsu[i]=i;
    for (int i=0; i<k; i++)
    {
        cin>>s;
        int sz=s.size();
        string a, b;
        opr=' ';
        for (int i=0; i<sz; i++)
        {
            if (s[i]=='<'||s[i]=='='||s[i]=='>') opr=s[i];
            else
            {
                if (opr==' ') a.push_back(s[i]);
                else b.push_back(s[i]);
            }
        }
        u=tonum(a);
        v=tonum(b);
        if (opr=='=') dsu[find(u)]=find(v);
        else
        {
            if (opr=='<') edg.push_back({u, v});
            else edg.push_back({v, u});
        }
    }
    for (auto [u, v]:edg) up[find(u)].push_back(find(v)), degup[find(v)]++, dn[find(v)].push_back(find(u)), degdn[find(u)]++;
    for (int i=1; i<=m; i++) if (find(i)==i&&degup[i]==0) lvlup[i]=0, q.push(i); 
    while (!q.empty())
    {
        auto u=q.front();
        q.pop();
        for (auto v:up[u]) if (--degup[v]==0) lvlup[v]=max(lvlup[v], lvlup[u]+1), q.push(v);
    }
    for (int i=1; i<=m; i++) if (find(i)==i&&degdn[i]==0) lvldn[i]=0, q.push(i);
    while (!q.empty())
    {
        auto u=q.front();
        q.pop();
        for (auto v:dn[u]) if (--degdn[v]==0) lvldn[v]=max(lvldn[v], lvldn[u]+1), q.push(v);
    }
    for (int i=1; i<=m; i++) if (find(i)==i&&lvlup[i]+lvldn[i]==n-1) res[i]=lvlup[i]+1;
    for (int i=1; i<=m; i++) 
    {
        if (res[find(i)]) cout<<"K"<<res[find(i)]<<'\n';
        else cout<<"?\n";
    }
}

• Subtask 1: 10 / 10
• Subtask 2: 40 / 40
• Subtask 3: 10 / 10
• Subtask 4: 40 / 40