Submission #788262

#	Time	Username	Problem	Language	Result	Execution time	Memory
788262		Username4132	Povjerenstvo (COI22_povjerenstvo)	C++14	33 / 100	3034 ms	86876 KiB

Main

#include<iostream>
#include<vector>
#include<algorithm>
#include<cassert>
using namespace std;
#define forn(i, n) for(int i=0; i<(int)n; ++i)
#define PB push_back

const int MAXN = 500010;
int n, m, cn;
bool vis[MAXN], del[MAXN], ans[MAXN], allow[MAXN];
vector<int> g[MAXN], gi[MAXN], order, lst;

void dfs1(int v){
    vis[v]=true;
    for(int to:g[v]) if(!vis[to] && !del[to]) dfs1(to);
    order.PB(v);
}

void dfs2(int v){
    vis[v]=true;
    for(int to:gi[v]) if(!vis[to] && !del[to]) dfs2(to);
    lst.PB(v);
}

void dfs3(int v, bool flag){
    del[v]=vis[v]=true;
    ans[v]=flag;
    for(int to:gi[v]) if(!del[to]){
        if(flag) del[to]=true;
        if(!vis[to] && allow[to]) dfs3(to, !flag);
    }
}

int main(){
    scanf("%d %d", &n, &m);
    forn(i, m){
        int a, b; scanf("%d %d", &a, &b); --a, --b;
        g[a].PB(b), gi[b].PB(a);
    }
    while(true){
        order.clear();
        lst.clear();
        forn(i, n) vis[i]=false;
        forn(i, n) if(!vis[i] && !del[i]) dfs1(i);
        if(order.empty()) break;
        reverse(order.begin(), order.end());
        forn(i, n) vis[i]=false;
        for(int el:order) if(!vis[el]) lst.clear(), dfs2(el);
        int v = lst.back();
        assert(!del[v]);
        forn(i, n) vis[i]=allow[i]=false;
        for(int el:lst) allow[el]=true;
        dfs3(v, true);
    }
    forn(i, n) cn+=ans[i];
    printf("%d\n", cn);
    forn(i, n) if(ans[i]) printf("%d ", i+1);
}

Compilation message (stderr)

Main.cpp: In function 'int main()':
Main.cpp:36:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   36 |     scanf("%d %d", &n, &m);
      |     ~~~~~^~~~~~~~~~~~~~~~~
Main.cpp:38:24: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   38 |         int a, b; scanf("%d %d", &a, &b); --a, --b;
      |                   ~~~~~^~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 13
• Subtask 2: 0 / 21
• Subtask 3: 33 / 33
• Subtask 4: 0 / 33