oj.uz

Submission #728643

# Submission time Handle Problem Language Result Execution time Memory
728643 2023-04-22T18:28:32 Z grogu Thousands Islands (IOI22_islands) C++17
55 / 100
 169 ms 41464 KB 
#include "islands.h"
#define here cerr<<"=======================\n"
#include <iostream>
#include <vector>
#include <variant>
#include <algorithm>
#include <set>
#define dbg(x) cerr<<#x<<": "<<x<<endl
#define ll int
#define pll pair<ll,ll>
#define pb push_back
#define popb pop_back
#define all(x_) x_.begin(), x_.end()
using namespace std;
#define maxn 1005
ll n,m;
vector<ll> g[maxn];
ll id[maxn][maxn];
vector<ll> allid[maxn][maxn];
set<pll> sss;
vector<ll> gen(vector<ll> v){
    vector<ll> ans;
    for(ll i = 0;i<=v.size()/2-1;i++) ans.pb(v[i]);
    for(ll i = v.size()-1;i>=v.size()/2;i--) ans.pb(v[i]);
    for(ll i = v.size()/2 - 1;i>=0;i--) ans.pb(v[i]);
    for(ll i = v.size()/2;i<=v.size()-1;i++) ans.pb(v[i]);
    return ans;
}
bool vis[maxn];
bool naso = 0;
ll x,y,tip;
vector<ll> cur;
void dfs1(ll u,ll p){
    vis[u] = 1;
    cur.pb(u);
    if(g[u].size()-(u!=p)>1){
        naso = 1;
        tip = 1;
        x = u;
        y = p;
        return;
    }
    for(ll s : g[u]){
        if(s==p) continue;
        if(vis[s]) continue;
        if(allid[u][s].size()>1){
            naso = 1;
            tip = 2;
            x = u;
            y = s;
            return;
        }
        dfs1(s,u);
        if(naso) return;
    }
    cur.popb();
}
bool sub = 1;
vector<ll> cyc;
ll in[maxn];
ll ti = 0;
void dfs2(ll u,ll p){
    vis[u] = 1;
    in[u] = 1;
    cur.pb(u);
    for(ll s : g[u]){
        if(vis[s]&&in[s]){
            while(cur.size()){
                cyc.pb(cur.back());
                if(cyc.back()==s) break;
                cur.popb();
            }
            naso = 1;
            return;
        }
        if(vis[s]) continue;
        dfs2(s,u);
        if(naso) return;
    }
    in[u] = 0;
    cur.popb();
}
void dfs3(ll u,ll p,ll en){
    cur.pb(u);
    if(u==en){
        naso = 1;
        return;
    }
    vis[u] = 1;
    for(ll s : g[u]){
        if(vis[s]) continue;
        dfs3(s,u,en);
        if(naso) return;
    }
    if(cur.size()) cur.popb();
}
variant<bool, vector<int>> find_journey(int N, int M, vector<int> U, vector<int> V) {
    n = N;
    m = M;
    for(ll &x : U) x++;
    for(ll &x : V) x++;
    if(sub&&n==2){
        vector<vector<ll> > cnt(3);
        for(ll i = 0;i<m;i++){
            ll x = U[i],y = V[i];
            cnt[x].pb(i);
        }
        bool ok = cnt[1].size()>=2&&cnt[2].size()>=1;
        if(!ok) return ok;
        ll x = cnt[1][0],y = cnt[1][1];
        ll z = cnt[2][0];
        vector<ll> ans;
        ans.pb(x);
        ans.pb(z);
        ans.pb(y);
        ans.pb(x);
        ans.pb(z);
        ans.pb(y);
        return ans;
    }
    for(ll i = 1;i<=n;i++) for(ll j = 1;j<=n;j++) id[i][j] = -1;
    for(ll i = 0;i<m;i++){
        ll x = U[i],y = V[i];
        if(id[x][y]==-1) g[x].pb(y);
        id[x][y] = i;
        allid[x][y].pb(i);
        sss.insert({x,y});
    }
    if(sub&&n<=400&&sss.size()==n*(n-1)&&m==n*(n-1)){
        ll x = id[1][2];
        ll y = id[2][3];
        ll z = id[3][1];
        ll rx = id[2][1];
        ll ry = id[3][2];
        ll rz = id[1][3];
        vector<ll> ans = gen({x,y,z,rx,ry,rz});
        return ans;
    }
    bool sub2 = m%2==0;
    for(ll i = 0;i<m;i+=2) sub2&=(U[i]==V[i+1]&&V[i]==U[i+1]);
    if(n<=1000&&sub2){
        dfs1(1,1);
        if(!naso) return naso;
        if(tip==1){
            ll A = -1,B = -1;
            for(ll s : g[x]){
                if(s==y) continue;
                if(A==-1) A = s;
                else if(B==-1) B = s;
            }
            ll x1 = id[x][A];
            ll rx1 = id[A][x];
            ll y1 = id[x][B];
            ll ry1 = id[B][x];
            vector<ll> ans;
            for(ll i = 0;i<cur.size()-1;i++) ans.pb(id[cur[i]][cur[i+1]]);
            ans.pb(x1);
            ans.pb(rx1);
            ans.pb(y1);
            ans.pb(ry1);
            ans.pb(rx1);
            ans.pb(x1);
            ans.pb(ry1);
            ans.pb(y1);
            for(ll i = cur.size()-2;i>=0;i--) ans.pb(id[cur[i]][cur[i+1]]);
            return ans;
        }else{
            ll x1 = allid[x][y][0];
            ll y1 = allid[x][y][1];
            ll rx1 = allid[y][x][0];
            ll ry1 = allid[y][x][1];
            vector<ll> ans;
            for(ll i = 0;i<cur.size()-1;i++) ans.pb(id[cur[i]][cur[i+1]]);
            ans.pb(x1);
            ans.pb(rx1);
            ans.pb(y1);
            ans.pb(x1);
            ans.pb(rx1);
            ans.pb(y1);
            for(ll i = cur.size()-2;i>=0;i--) ans.pb(id[cur[i]][cur[i+1]]);
            return ans;
        }
    }
    dfs2(1,1);
    if(!naso) return naso;
    for(ll i = 1;i<=n;i++) vis[i] = 0;
    reverse(all(cyc));
    cur.clear();
    naso = 0;
    dfs3(1,1,cyc[0]);
    cyc.pb(cyc[0]);
    vector<ll> ans;
    for(ll i = 0;i<cur.size()-1;i++) ans.pb(id[cur[i]][cur[i+1]]);
    for(ll i = 0;i<cyc.size()-1;i++) ans.pb(allid[cyc[i]][cyc[i+1]][0]);
    for(ll i = 0;i<cyc.size()-1;i++) ans.pb(allid[cyc[i]][cyc[i+1]][1]);
    for(ll i = cyc.size()-2;i>=0;i--) ans.pb(allid[cyc[i]][cyc[i+1]][0]);
    for(ll i = cyc.size()-2;i>=0;i--) ans.pb(allid[cyc[i]][cyc[i+1]][1]);
    for(ll i = cur.size()-2;i>=0;i--) ans.pb(id[cur[i]][cur[i+1]]);
    return ans;
}
/**
5 8
0 1
1 0
1 2
2 1
2 3
3 2
2 4
4 2

7 14
0 1
0 1
1 2
1 2
2 3
2 3
3 4
3 4
4 5
4 5
5 6
5 6
6 3
6 3
**/

Compilation message

islands.cpp: In function 'std::vector<int> gen(std::vector<int>)':
islands.cpp:23:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   23 |     for(ll i = 0;i<=v.size()/2-1;i++) ans.pb(v[i]);
      |                  ~^~~~~~~~~~~~~~
islands.cpp:24:28: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   24 |     for(ll i = v.size()-1;i>=v.size()/2;i--) ans.pb(v[i]);
      |                           ~^~~~~~~~~~~~
islands.cpp:26:28: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   26 |     for(ll i = v.size()/2;i<=v.size()-1;i++) ans.pb(v[i]);
      |                           ~^~~~~~~~~~~~
islands.cpp: In function 'std::variant<bool, std::vector<int, std::allocator<int> > > find_journey(int, int, std::vector<int>, std::vector<int>)':
islands.cpp:105:25: warning: unused variable 'y' [-Wunused-variable]
  105 |             ll x = U[i],y = V[i];
      |                         ^
islands.cpp:129:31: warning: comparison of integer expressions of different signedness: 'std::set<std::pair<int, int> >::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
  129 |     if(sub&&n<=400&&sss.size()==n*(n-1)&&m==n*(n-1)){
      |                     ~~~~~~~~~~^~~~~~~~~
islands.cpp:156:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  156 |             for(ll i = 0;i<cur.size()-1;i++) ans.pb(id[cur[i]][cur[i+1]]);
      |                          ~^~~~~~~~~~~~~
islands.cpp:173:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  173 |             for(ll i = 0;i<cur.size()-1;i++) ans.pb(id[cur[i]][cur[i+1]]);
      |                          ~^~~~~~~~~~~~~
islands.cpp:171:16: warning: unused variable 'ry1' [-Wunused-variable]
  171 |             ll ry1 = allid[y][x][1];
      |                ^~~
islands.cpp:193:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  193 |     for(ll i = 0;i<cur.size()-1;i++) ans.pb(id[cur[i]][cur[i+1]]);
      |                  ~^~~~~~~~~~~~~
islands.cpp:194:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  194 |     for(ll i = 0;i<cyc.size()-1;i++) ans.pb(allid[cyc[i]][cyc[i+1]][0]);
      |                  ~^~~~~~~~~~~~~
islands.cpp:195:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  195 |     for(ll i = 0;i<cyc.size()-1;i++) ans.pb(allid[cyc[i]][cyc[i+1]][1]);
      |                  ~^~~~~~~~~~~~~

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 12 ms 24020 KB Output is correct
2 Correct 13 ms 24148 KB Output is correct
3 Correct 13 ms 24020 KB Output is correct
4 Correct 12 ms 24020 KB Output is correct
5 Correct 14 ms 23964 KB Output is correct
6 Correct 13 ms 24028 KB Output is correct
7 Correct 47 ms 28104 KB Output is correct

Subtask #2
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 12 ms 24020 KB Output is correct
2 Correct 13 ms 23952 KB Output is correct
3 Correct 12 ms 24068 KB Output is correct
4 Correct 12 ms 24072 KB Output is correct
5 Correct 13 ms 24032 KB Output is correct
6 Correct 159 ms 41464 KB Output is correct

Subtask #3
21.0 / 21.0

# Verdict Execution time Memory Grader output
1 Correct 18 ms 28372 KB Output is correct
2 Correct 14 ms 24448 KB Output is correct
3 Correct 13 ms 23972 KB Output is correct
4 Correct 14 ms 24020 KB Output is correct
5 Correct 20 ms 28244 KB Output is correct
6 Correct 12 ms 24048 KB Output is correct
7 Correct 15 ms 28056 KB Output is correct
8 Correct 14 ms 24404 KB Output is correct
9 Correct 13 ms 24472 KB Output is correct
10 Correct 17 ms 28244 KB Output is correct
11 Correct 14 ms 24020 KB Output is correct
12 Correct 16 ms 28244 KB Output is correct
13 Correct 13 ms 24404 KB Output is correct
14 Correct 13 ms 24376 KB Output is correct
15 Correct 12 ms 24360 KB Output is correct
16 Correct 13 ms 24412 KB Output is correct
17 Correct 117 ms 37432 KB Output is correct
18 Correct 86 ms 35680 KB Output is correct
19 Correct 13 ms 24044 KB Output is correct
20 Correct 13 ms 24004 KB Output is correct
21 Correct 13 ms 24020 KB Output is correct
22 Correct 12 ms 24104 KB Output is correct
23 Correct 169 ms 41420 KB Output is correct

Subtask #4
24.0 / 24.0

# Verdict Execution time Memory Grader output
1 Correct 12 ms 24404 KB Output is correct
2 Correct 14 ms 24532 KB Output is correct
3 Correct 62 ms 28768 KB Output is correct
4 Correct 102 ms 36584 KB Output is correct
5 Correct 20 ms 27828 KB Output is correct
6 Correct 16 ms 27808 KB Output is correct
7 Correct 13 ms 24020 KB Output is correct
8 Correct 15 ms 24032 KB Output is correct
9 Correct 12 ms 24020 KB Output is correct
10 Correct 17 ms 28164 KB Output is correct
11 Correct 20 ms 28244 KB Output is correct
12 Correct 20 ms 28244 KB Output is correct
13 Correct 16 ms 28244 KB Output is correct
14 Correct 16 ms 28124 KB Output is correct
15 Correct 17 ms 28244 KB Output is correct
16 Correct 17 ms 28116 KB Output is correct
17 Correct 14 ms 24152 KB Output is correct
18 Correct 16 ms 28124 KB Output is correct
19 Correct 15 ms 28104 KB Output is correct
20 Correct 77 ms 29084 KB Output is correct
21 Correct 114 ms 37628 KB Output is correct
22 Correct 15 ms 28116 KB Output is correct
23 Correct 14 ms 28040 KB Output is correct
24 Correct 12 ms 24404 KB Output is correct
25 Correct 13 ms 24532 KB Output is correct
26 Correct 16 ms 28244 KB Output is correct
27 Correct 109 ms 35684 KB Output is correct
28 Correct 109 ms 36300 KB Output is correct
29 Correct 13 ms 24404 KB Output is correct
30 Correct 134 ms 38688 KB Output is correct
31 Correct 13 ms 24096 KB Output is correct
32 Correct 103 ms 36592 KB Output is correct
33 Correct 68 ms 29092 KB Output is correct
34 Correct 64 ms 33640 KB Output is correct
35 Correct 14 ms 26360 KB Output is correct
36 Correct 94 ms 35800 KB Output is correct
37 Correct 116 ms 38196 KB Output is correct
38 Correct 15 ms 26068 KB Output is correct
39 Correct 87 ms 33204 KB Output is correct
40 Correct 16 ms 28116 KB Output is correct
41 Correct 127 ms 38728 KB Output is correct
42 Correct 105 ms 36544 KB Output is correct
43 Correct 13 ms 24404 KB Output is correct
44 Correct 17 ms 28180 KB Output is correct
45 Correct 16 ms 28216 KB Output is correct
46 Correct 51 ms 32460 KB Output is correct

Subtask #5
0.0 / 45.0

# Verdict Execution time Memory Grader output
1 Correct 12 ms 24020 KB Output is correct
2 Correct 13 ms 24148 KB Output is correct
3 Correct 13 ms 24020 KB Output is correct
4 Correct 12 ms 24020 KB Output is correct
5 Correct 14 ms 23964 KB Output is correct
6 Correct 13 ms 24028 KB Output is correct
7 Correct 47 ms 28104 KB Output is correct
8 Correct 12 ms 24020 KB Output is correct
9 Correct 13 ms 23952 KB Output is correct
10 Correct 12 ms 24068 KB Output is correct
11 Correct 12 ms 24072 KB Output is correct
12 Correct 13 ms 24032 KB Output is correct
13 Correct 159 ms 41464 KB Output is correct
14 Correct 18 ms 28372 KB Output is correct
15 Correct 14 ms 24448 KB Output is correct
16 Correct 13 ms 23972 KB Output is correct
17 Correct 14 ms 24020 KB Output is correct
18 Correct 20 ms 28244 KB Output is correct
19 Correct 12 ms 24048 KB Output is correct
20 Correct 15 ms 28056 KB Output is correct
21 Correct 14 ms 24404 KB Output is correct
22 Correct 13 ms 24472 KB Output is correct
23 Correct 17 ms 28244 KB Output is correct
24 Correct 14 ms 24020 KB Output is correct
25 Correct 16 ms 28244 KB Output is correct
26 Correct 13 ms 24404 KB Output is correct
27 Correct 13 ms 24376 KB Output is correct
28 Correct 12 ms 24360 KB Output is correct
29 Correct 13 ms 24412 KB Output is correct
30 Correct 117 ms 37432 KB Output is correct
31 Correct 86 ms 35680 KB Output is correct
32 Correct 13 ms 24044 KB Output is correct
33 Correct 13 ms 24004 KB Output is correct
34 Correct 13 ms 24020 KB Output is correct
35 Correct 12 ms 24104 KB Output is correct
36 Correct 169 ms 41420 KB Output is correct
37 Partially correct 12 ms 24036 KB Output is partially correct
38 Correct 14 ms 23956 KB Output is correct
39 Incorrect 13 ms 24404 KB Output isn't correct
40 Halted 0 ms 0 KB -