Submission #142819

#	Time	Username	Problem	Language	Result	Execution time	Memory
142819		popovicirobert	Information (CEOI08_information)	C++14	100 / 100	227 ms	19676 KiB

information

#include <bits/stdc++.h>
#define lsb(x) (x & (-x))
#define ll long long
#define ull unsigned long long



/*const int MOD = 998244353;

inline int lgput(int a, int b) {
    int ans = 1;
    while(b > 0) {
        if(b & 1) ans = (1LL * ans * a) % MOD;
        b >>= 1;
        a = (1LL * a * a) % MOD;
    }
    return ans;
}

inline void mod(int &x) {
    if(x >= MOD)
        x -= MOD;
}

inline void add(int &x, int y) {
    x += y;
    mod(x);
}

inline void sub(int &x, int y) {
    x += MOD - y;
    mod(x);
}

inline void mul(int &x, int y) {
    x = (1LL * x * y) % MOD;
}

inline int inv(int x) {
    return lgput(x, MOD - 2);
}*/

/*int fact[], invfact[];

inline void prec(int n) {
    fact[0] = 1;
    for(int i = 1; i <= n; i++) {
        fact[i] = (1LL * fact[i - 1] * i) % MOD;
    }
    invfact[n] = lgput(fact[n], MOD - 2);
    for(int i = n - 1; i >= 0; i--) {
        invfact[i] = (1LL * invfact[i + 1] * (i + 1)) % MOD;
    }
}

inline int comb(int n, int k) {
    if(n < k) return 0;
    return (1LL * fact[n] * (1LL * invfact[k] * invfact[n - k] % MOD)) % MOD;
}*/

using namespace std;

const int MAXN = 2000;
const int MAXM = (int) 1e6;

vector < pair <short, int> > g[MAXN + 1], up[MAXN + 1];
int idl[MAXN + 1], idr[MAXN + 1], sz;
char vis[MAXN + 1], sol[MAXM + 1];

void dfs(int nod) {
    idl[nod] = ++sz;
    vis[nod] = 1;
    for(auto it : g[nod]) {
        if(vis[it.first] == 0) {
            dfs(it.first);
            sol[it.second] = 1;
        }
    }
    idr[nod] = sz;
}

void dfs1(int nod) {
    vis[nod] = 1;
    for(auto it : g[nod]) {
        if(vis[it.first]) continue;
        if(sol[it.second] == 0) {
            sol[it.second] = 2;
            dfs1(it.first);
        }
        else if(up[it.first].size()) {
            sol[it.second] = 2, sol[up[it.first].back().second] = 1;
            up[it.first].pop_back();
            dfs1(it.first);
        }
    }
}


int main() {
#ifdef HOME
    ifstream cin("A.in");
    ofstream cout("A.out");
#endif
    int n, m, i;
    ios::sync_with_stdio(false);
    cin.tie(0), cout.tie(0);

    cin >> n >> m;
    for(i = 1; i <= m; i++) {
        int x, y;
        cin >> x >> y;
        g[x].push_back({y, i});
    }
    dfs(1);
    for(i = 1; i <= n; i++) {
        for(auto it : g[i]) {
            if(idl[i] <= idl[it.first] && idr[it.first] <= idr[i] && sol[it.second] == 0) {
                up[it.first].push_back({i, it.second});
            }
        }
    }
    fill(vis, vis + n + 1, 0);
    dfs1(1);

    vector <int> a, b;
    for(i = 1; i <= m; i++) {
        if(sol[i] == 1) a.push_back(i);
        if(sol[i] == 2) b.push_back(i);
    }
    if(a.size() < n - 1 || b.size() < n - 1) {
        cout << "NONE";
        return 0;
    }
    for(auto it : a) {
        cout << it << " ";
    }
    cout << "\n";
    for(auto it : b) {
        cout << it << " ";
    }

    return 0;
}

Compilation message (stderr)

information.cpp: In function 'int main()':
information.cpp:130:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     if(a.size() < n - 1 || b.size() < n - 1) {
        ~~~~~~~~~^~~~~~~
information.cpp:130:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     if(a.size() < n - 1 || b.size() < n - 1) {
                            ~~~~~~~~~^~~~~~~

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