Submission #974560

#	Time	Username	Problem	Language	Result	Execution time	Memory
974560		onlk97	Keys (IOI21_keys)	C++17	9 / 100	178 ms	61420 KiB

keys

#include <vector>
#include <bits/stdc++.h>
using namespace std;
vector <int> in[300010],out[300010];
bool visited[300010];
stack <int> st;
void dfs1(int cur){
    visited[cur]=1;
    for (int i:out[cur]){
        if (!visited[i]) dfs1(i);
    }
    st.push(cur);
}
vector <vector <int> > scc;
int belong[300010],idx;
vector <int> cc;
void dfs2(int cur){
    cc.push_back(cur);
    belong[cur]=idx;
    visited[cur]=1;
    for (int i:in[cur]){
        if (!visited[i]) dfs2(i);
    }
}
vector <int> find_reachable(vector <int> r,vector <int> u,vector <int> v,vector <int> c){
    int n=r.size(),m=u.size();
    for (int i=0; i<m; i++){
        if (r[u[i]]==c[i]){
            out[u[i]].push_back(v[i]);
            in[v[i]].push_back(u[i]);
        }
        if (r[v[i]]==c[i]){
            out[v[i]].push_back(u[i]);
            in[u[i]].push_back(v[i]);
        }
    }
    for (int i=0; i<n; i++){
        if (!visited[i]) dfs1(i);
    }
    for (int i=0; i<n; i++) visited[i]=0;
    while (!st.empty()){
        int tp=st.top(); st.pop();
        if (visited[tp]) continue;
        dfs2(tp);
        scc.push_back(cc);
        idx++;
        cc.clear();
    }
    vector <int> safe;
    for (int i=0; i<n; i++){
        int ok=1;
        for (int j:out[i]){
            if (belong[i]!=belong[j]) ok=0;
        }
        safe.push_back(ok);
    }
    int mn=1e9;
    for (auto i:scc){
        bool ok=1;
        for (int j:i){
            if (!safe[j]) ok=0;
        }
        if (ok) mn=min(mn,(int)i.size());
    }
    vector <int> ans(n,0);
    for (auto i:scc){
        bool ok=1;
        for (int j:i){
            if (!safe[j]) ok=0;
        }
        if (ok&&i.size()==mn){
            for (int j:i) ans[j]=1;
        }
    }
    return ans;
}

Compilation message (stderr)

keys.cpp: In function 'std::vector<int> find_reachable(std::vector<int>, std::vector<int>, std::vector<int>, std::vector<int>)':
keys.cpp:71:25: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   71 |         if (ok&&i.size()==mn){
      |                 ~~~~~~~~^~~~

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