Submission #436385

#	Time	Username	Problem	Language	Result	Execution time	Memory
436385		CodePlatina	Keys (IOI21_keys)	C++17	20 / 100	1131 ms	315036 KiB

keys

#include <vector>
#include <algorithm>
#include <tuple>
#define pii pair<int, int>
#define tiii tuple<int, int, int>
#define ff first
#define ss second

using namespace std;

int n, N;
const int INF = (int)1e9 + 7;
vector<int> R, C;
vector<vector<int>> gph[303030];
vector<int> edge[303030];
vector<bool> key[303030];
vector<pii> ran;
int ord[303030];
int rev[303030];
int cnt = 0;
int val = 0;

bool dfs(int x)
{
    int ret = ord[x] = ++cnt;
    rev[cnt] = x;

    edge[x].resize(N, INF);
    key[x].resize(N, false);

    vector<int> Q;
    Q.push_back(R[x]);

    while(Q.size())
    {
        int c = Q.back(); Q.pop_back();
        if(key[x][c]) continue;
        key[x][c] = true;

        for(int y : gph[x][c])
        {
            if(!ord[y])
            {
                if(dfs(y)) return true;
                for(int i = 0; i < N; ++i)
                {
                    edge[x][i] = min(edge[x][i], edge[y][i]);
                    if(!key[x][i] && key[y][i]) Q.push_back(i);
                }
            }
            else edge[x][c] = min(edge[x][c], ord[y]);
        }
    }

    for(int i = 0; i < N; ++i)
    {
        if(key[x][i]) ret = min(ret, edge[x][i]);
        else for(int y : gph[x][i]) if(!ord[y]) edge[x][i] = min(edge[x][i], ord[y]);
    }

    if(ret < val) { val = ord[x] + 1; return true; }
    if(ret >= ord[x])
    {
        ran.push_back({ord[x], cnt});
        val = ord[x] + 1;
        return true;
    }

    return false;
}


vector<int> find_reachable(vector<int> r, vector<int> u, vector<int> v, vector<int> c)
{
    n = r.size();
    int m = u.size();
    N = 0;
    for(int i = 0; i < n; ++i) N = max(N, r[i]);
    for(int i = 0; i < m; ++i) N = max(N, c[i]);
    ++N;
    for(int i = 0; i < n; ++i) gph[i].resize(N);
    R = r, C = c;

    for(int i = 0; i < m; ++i)
    {
        gph[u[i]][c[i]].push_back(v[i]);
        gph[v[i]][c[i]].push_back(u[i]);
    }

    for(int i = 0; i < n; ++i) if(!ord[i]) dfs(i);

    int mn = INF;
    for(auto [x, y] : ran) mn = min(mn, y - x);
    vector<int> ans(n);
    for(auto [x, y] : ran) if(mn == y - x)
    {
        for(int i = x; i <= y; ++i)
            ans[rev[i]] = 1;
    }
    return ans;
}

• Subtask 1: 9 / 9
• Subtask 2: 11 / 11
• Subtask 3: 0 / 17
• Subtask 4: 0 / 30
• Subtask 5: 0 / 33