oj.uz

Submission #581338

# Submission time Handle Problem Language Result Execution time Memory
581338 2022-06-22T13:38:18 Z Lobo Alternating Current (BOI18_alternating) C++17
19 / 100
 61 ms 11876 KB 
#include<bits/stdc++.h>
using namespace std;

const long long inf = (long long) 1e18 + 10;
const int inf1 = (int) 1e9 + 10;
#define int long long
#define dbl long double
#define endl '\n'
#define sc second
#define fr first
#define mp make_pair
#define pb push_back
#define all(x) x.begin(), x.end()

const int maxn = 2e5+10;

int n, m, pai[maxn], ps[maxn], ans[maxn];

int find(int v) {
    if(pai[v] == v) return v;
    return pai[v] = find(pai[v]);
}

bool cmp(pair<pair<int,int>,int> a, pair<pair<int,int>,int> b) {
    if(a.fr.fr == b.fr.fr) {
        return a.fr.sc > b.fr.sc;
    }
    return a.fr.fr < b.fr.fr;
}

void solve() {
    cin >> n >> m;
    vector<pair<pair<int,int>,int>> segs;
    vector<pair<int,int>> vec;
    for(int i = 0; i < m; i++) {
        int a,b; cin >> a >> b;
        vec.pb(mp(a,b));
        pai[i] = i;
        if(b >= a) {
            ps[a]++;
            ps[b+1]--;
            ps[a+n]++;
            ps[b+n+1]--;

            segs.pb(mp(mp(a,b),i));
            // segs.pb(mp(mp(a+n,b+n),i));
        }
        else {
            ps[a]++;
            ps[b+n+1]--;
            ps[1]++;
            ps[b+1]--;
            ps[a+n]++;
            ps[2*n+1]--;
            segs.pb(mp(mp(a,b+n),i));
        }
    }

    sort(all(segs),cmp); //menor L, maior R
    priority_queue<pair<pair<int,int>,int>,vector<pair<pair<int,int>,int>>,greater<pair<pair<int,int>,int>>> pq;
    for(auto X : segs) {
        int l = X.fr.fr;
        int r = X.fr.sc;
        int id = X.sc;
        // cout << l << " " << r << " -" << id << endl;
        while(pq.size() && pq.top().fr.sc < r) pq.pop();
        if(pq.size() && pq.top().fr.fr <= l) {
            pai[id] = pq.top().sc;
            // cout << " " << pai[id] << endl;
        }
        else {
            pq.push(mp(mp(l,r),id));
        }
    }

    segs.clear();
    for(int i = 0; i < m; i++) {
        // cout << i << " " << pai[i] << endl;
        if(pai[i] == i) {
            int a = vec[i].fr;
            int b = vec[i].sc;
            if(b >= a) {
                segs.pb(mp(mp(a,b),i));
            }
            else {
                segs.pb(mp(mp(a,b+n),i));
            }
        }
    }
    sort(all(segs));

    for(int i = 0; i < m; i++) {
        if(pai[i] == i) continue;
        int l1 = vec[i].fr;
        int r1 = vec[i].sc;
        //ve o ultimo com l menor ou igual a l1
        auto it = lower_bound(all(segs),mp(mp(l1,inf),0LL));
        if(it != segs.end()) {
            int l2,r2,id;
            l2 = it->fr.fr;
            r2 = it->fr.sc;
            id = it->sc;
            //ve se da certo com esse
            if(l1 >= l2 && r1 <= r2) {
                pai[i] = id;
                continue;
            }
        }

        //tenta com l1+n e r1+n
        l1+= n;
        r1+= n;
        it = lower_bound(all(segs),mp(mp(l1,inf),0LL));
        if(it != segs.end()) {
            int l2,r2,id;
            l2 = it->fr.fr;
            r2 = it->fr.sc;
            id = it->sc;
            //ve se da certo com esse
            if(l1 >= l2 && r1 <= r2) {
                pai[i] = id;
                continue;
            }
        }
    }

    bool ok = true;
    for(int i = 1; i <= 2*n; i++) {
        ps[i]+=ps[i-1];
        if(ps[i] < 2) ok = false;
    }
    if(!ok) {
        cout << "impossible" << endl;
        return;
    }

    if((((int) segs.size())&1) == 0) {
        for(int i = 0; i < segs.size(); i++) {
            int id = segs[i].sc;
            ans[id] = i&1;
        }
        for(int i = 0; i < m; i++) {
            if(pai[i] == i) continue;
            ans[i] = ans[pai[i]]^1;
        }

        for(int i = 0; i < m; i++) {
            cout << ans[i];
        }cout << endl;
    }
    else {
        if(segs.size() == 1) {
            ans[segs[0].sc] = 1;

            int ps0[maxn], ps1[maxn];
            for(int i = 0; i <= n; i++) {
                ps0[i] = ps1[0] = 0;
            }
            for(auto x : segs) {
                // cout << x.fr.fr << " " << x.fr.sc << " " << x.sc << endl;
            }

            for(int i = 0; i < m; i++) {
                // cout << i << " -> " << vec[pai[i]].fr << " " << vec[pai[i]].sc << endl;
                int a = vec[i].fr;
                int b = vec[i].sc;
                if(b >= a) {
                    if(ans[i] == 0) {
                        ps0[a]++;
                        ps0[b+1]--;
                    }
                    else {
                        ps1[a]++;
                        ps1[b+1]--;
                    }
                }
                else {
                    if(ans[i] == 0) {
                        ps0[b]++;
                        ps0[1]++;
                        ps0[a+1]--;
                    }
                    else {
                        ps1[b]++;
                        ps1[1]++;
                        ps1[a+1]--;
                    }
                }
            }

            bool okk = false;
            for(int i = 1; i <= n; i++) {
                ps0[i]+= ps0[i-1];
                ps1[i]+= ps1[i-1];
                if(ps0[i] == 0 || ps1[i] == 0) {
                    okk = true;
                }
            }
            if(okk) {
                cout << n<<"--"<<m<<"---";
                cout << segs[0].fr.fr<<"--"<<segs[0].fr.sc;
                return;
            }

            for(int i = 0; i < m; i++) {
                cout << ans[i];
            }cout << endl;
            return;
        }
        bool ok = false;
        for(int i = 0; i+1 < segs.size(); i++) {
            int l1 = segs[i].fr.fr;
            int r1 = segs[i].fr.sc;
            int l2 = segs[i+1].fr.fr;
            int r2 = segs[i+1].fr.sc;

            //a area coberta por dois é l2 até r1
            int l = l2;
            int r = r1;
            bool ok1 = true;
            for(int i = l; i <= r; i++) {
                if(ps[i] < 3) {
                    ok1 = false;
                    break;
                }
            }
            if(ok1) {
                int cnt = 0;
                for(int j = i+1; j < segs.size(); j++) {
                    int id = segs[j].sc;
                    ans[id]=cnt;
                    cnt^=1;
                }
                for(int j = 0; j <= i; j++) {
                    int id = segs[j].sc;
                    ans[id]=cnt;
                    cnt^=1;
                }
                ok = true;
                break;
            }
        }

        if(ok == false) {
            //ultimo com o primeiro
            int l1 = segs.back().fr.fr;
            int r1 = segs.back().fr.sc;
            int l2 = segs[0].fr.fr+n;
            int r2 = segs[0].fr.sc+n;
            int l = l2;
            int r = r1;
            bool ok1 = true;
            for(int i = l; i <= r; i++) {
                if(ps[i] < 3) {
                    ok1 = false;
                    break;
                }
            }
            if(ok1) {
                int cnt = 0;
                for(int j = 0; j < segs.size(); j++) {
                    int id = segs[j].sc;
                    ans[id]=cnt;
                    cnt^=1;
                }
                ok = true;
            }
 
        }
        if(ok == false) {
            cout << "impossible" << endl;
            return;
        }
        for(int i = 0; i < m; i++) {
            if(pai[i] == i) continue;
            ans[i] = ans[pai[i]]^1;
        }
        for(int i = 0; i < m; i++) {
            cout << ans[i];
        }cout << endl;

    }






    int ps0[maxn], ps1[maxn];
    for(int i = 0; i <= n; i++) {
        ps0[i] = ps1[0] = 0;
    }
    for(auto x : segs) {
        // cout << x.fr.fr << " " << x.fr.sc << " " << x.sc << endl;
    }

    for(int i = 0; i < m; i++) {
        // cout << i << " -> " << vec[pai[i]].fr << " " << vec[pai[i]].sc << endl;
        int a = vec[i].fr;
        int b = vec[i].sc;
        if(b >= a) {
            if(ans[i] == 0) {
                ps0[a]++;
                ps0[b+1]--;
            }
            else {
                ps1[a]++;
                ps1[b+1]--;
            }
        }
        else {
            if(ans[i] == 0) {
                ps0[b]++;
                ps0[1]++;
                ps0[a+1]--;
            }
            else {
                ps1[b]++;
                ps1[1]++;
                ps1[a+1]--;
            }
        }
    }

    bool okk = false;
    for(int i = 1; i <= n; i++) {
        ps0[i]+= ps0[i-1];
        ps1[i]+= ps1[i-1];
        if(ps0[i] == 0 || ps1[i] == 0) {
            okk = true;
        }
    }
    if(okk) {
        cout << "penis";
    }cout << endl;

}

int32_t main() {
    ios::sync_with_stdio(false); cin.tie(0);

    // freopen("in.in", "r", stdin);
    // freopen("out.out", "w", stdout);
    int tt = 1;
    // cin >> tt;
    while(tt--) {
        solve();
    }

}

Compilation message

alternating.cpp: In function 'void solve()':
alternating.cpp:138:26: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<std::pair<std::pair<long long int, long long int>, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  138 |         for(int i = 0; i < segs.size(); i++) {
      |                        ~~^~~~~~~~~~~~~
alternating.cpp:159:22: warning: variable 'x' set but not used [-Wunused-but-set-variable]
  159 |             for(auto x : segs) {
      |                      ^
alternating.cpp:211:28: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<std::pair<std::pair<long long int, long long int>, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  211 |         for(int i = 0; i+1 < segs.size(); i++) {
      |                        ~~~~^~~~~~~~~~~~~
alternating.cpp:229:36: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<std::pair<std::pair<long long int, long long int>, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  229 |                 for(int j = i+1; j < segs.size(); j++) {
      |                                  ~~^~~~~~~~~~~~~
alternating.cpp:212:17: warning: unused variable 'l1' [-Wunused-variable]
  212 |             int l1 = segs[i].fr.fr;
      |                 ^~
alternating.cpp:215:17: warning: unused variable 'r2' [-Wunused-variable]
  215 |             int r2 = segs[i+1].fr.sc;
      |                 ^~
alternating.cpp:261:34: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<std::pair<std::pair<long long int, long long int>, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  261 |                 for(int j = 0; j < segs.size(); j++) {
      |                                ~~^~~~~~~~~~~~~
alternating.cpp:246:17: warning: unused variable 'l1' [-Wunused-variable]
  246 |             int l1 = segs.back().fr.fr;
      |                 ^~
alternating.cpp:249:17: warning: unused variable 'r2' [-Wunused-variable]
  249 |             int r2 = segs[0].fr.sc+n;
      |                 ^~
alternating.cpp:293:14: warning: variable 'x' set but not used [-Wunused-but-set-variable]
  293 |     for(auto x : segs) {
      |              ^

Subtask #1
0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 3412 KB Output is correct
2 Correct 2 ms 3412 KB Output is correct
3 Correct 2 ms 3412 KB Output is correct
4 Correct 2 ms 3412 KB Output is correct
5 Correct 2 ms 3412 KB Output is correct
6 Correct 2 ms 3412 KB Output is correct
7 Correct 2 ms 3412 KB Output is correct
8 Correct 2 ms 3412 KB Output is correct
9 Correct 2 ms 3412 KB Output is correct
10 Correct 2 ms 3412 KB Output is correct
11 Correct 2 ms 3412 KB Output is correct
12 Incorrect 2 ms 3412 KB no wires in direction 0 between segments 6 and 7
13 Halted 0 ms 0 KB -

Subtask #2
0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 3412 KB Output is correct
2 Correct 2 ms 3412 KB Output is correct
3 Correct 2 ms 3412 KB Output is correct
4 Correct 2 ms 3412 KB Output is correct
5 Correct 2 ms 3412 KB Output is correct
6 Correct 2 ms 3412 KB Output is correct
7 Correct 2 ms 3412 KB Output is correct
8 Correct 2 ms 3412 KB Output is correct
9 Correct 2 ms 3412 KB Output is correct
10 Correct 2 ms 3412 KB Output is correct
11 Correct 2 ms 3412 KB Output is correct
12 Incorrect 2 ms 3412 KB no wires in direction 0 between segments 6 and 7
13 Halted 0 ms 0 KB -

Subtask #3
0 / 22.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 3412 KB Output is correct
2 Correct 2 ms 3412 KB Output is correct
3 Correct 2 ms 3412 KB Output is correct
4 Correct 2 ms 3412 KB Output is correct
5 Correct 2 ms 3412 KB Output is correct
6 Correct 2 ms 3412 KB Output is correct
7 Correct 2 ms 3412 KB Output is correct
8 Correct 2 ms 3412 KB Output is correct
9 Correct 2 ms 3412 KB Output is correct
10 Correct 2 ms 3412 KB Output is correct
11 Correct 2 ms 3412 KB Output is correct
12 Incorrect 2 ms 3412 KB no wires in direction 0 between segments 6 and 7
13 Halted 0 ms 0 KB -

Subtask #4
19.0 / 19.0

# Verdict Execution time Memory Grader output
1 Correct 31 ms 9856 KB Output is correct
2 Correct 4 ms 4948 KB Output is correct
3 Correct 20 ms 7508 KB Output is correct
4 Correct 18 ms 7528 KB Output is correct
5 Correct 58 ms 10456 KB Output is correct
6 Correct 55 ms 9840 KB Output is correct
7 Correct 57 ms 10236 KB Output is correct
8 Correct 5 ms 5332 KB Output is correct
9 Correct 4 ms 4948 KB Output is correct
10 Correct 61 ms 10704 KB Output is correct
11 Correct 44 ms 9772 KB Output is correct
12 Correct 48 ms 9680 KB Output is correct
13 Correct 5 ms 4948 KB Output is correct
14 Correct 3 ms 4948 KB Output is correct
15 Correct 51 ms 10748 KB Output is correct
16 Correct 18 ms 8020 KB Output is correct
17 Correct 49 ms 11876 KB Output is correct
18 Correct 40 ms 10096 KB Output is correct
19 Correct 7 ms 5512 KB Output is correct
20 Correct 56 ms 11020 KB Output is correct

Subtask #5
0 / 26.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 3412 KB Output is correct
2 Correct 2 ms 3412 KB Output is correct
3 Correct 2 ms 3412 KB Output is correct
4 Correct 2 ms 3412 KB Output is correct
5 Correct 2 ms 3412 KB Output is correct
6 Correct 2 ms 3412 KB Output is correct
7 Correct 2 ms 3412 KB Output is correct
8 Correct 2 ms 3412 KB Output is correct
9 Correct 2 ms 3412 KB Output is correct
10 Correct 2 ms 3412 KB Output is correct
11 Correct 2 ms 3412 KB Output is correct
12 Incorrect 2 ms 3412 KB no wires in direction 0 between segments 6 and 7
13 Halted 0 ms 0 KB -