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Submission #907281

# Submission time Handle Problem Language Result Execution time Memory
907281 2024-01-15T10:50:56 Z abcvuitunggio Thousands Islands (IOI22_islands) C++17
24 / 100
 1000 ms 31580 KB 
#include "islands.h"
#include <variant>
#include <vector>
#include <cstring>
#include <algorithm>
using namespace std;
vector <int> u,v,ke[200001],ke2[200001],adj[200001],boring,fun,res,ve;
int n,m,ch[200001],pos[200001],deg[200001],x;
bool C=1;
pair <vector <int>, vector <int>> dfs(int s, int x){
    vector <int> ve,cycle;
    memset(pos,-1,sizeof(pos));
    ve.push_back(x);
    pos[x]=0;
    x=u[x]^v[x]^s;
    while (true){
        int i=adj[x][0];
        int y=u[i]^v[i]^x;
        x=y;
        if (pos[i]!=-1){
            x=i;
            break;
        }
        pos[i]=ve.size();
        ve.push_back(i);
    }
    for (int i=pos[x];i<ve.size();i++)
        cycle.push_back(ve[i]);
    while (ve.size()>pos[x])
        ve.pop_back();
    return {ve,cycle};
}
bool check(vector <int> a, vector <int> b){
    if (a.size()!=b.size())
        return false;
    memset(ch,0,sizeof(ch));
    for (int i:a)
        ch[i]=1;
    int cnt=0;
    for (int i:b)
        cnt+=ch[i];
    return (cnt==a.size());
}
vector <int> rev(vector <int> v){
    reverse(v.begin(),v.end());
    return v;
}
vector <int> operator +(vector <int> a, vector <int> b){
    for (int i:b)
        a.push_back(i);
    return a;
}
void strain(){
    while (deg[x]==1){
        for (int i:ke[x]){
            int y=u[i]^v[i]^x;
            if (!ch[y]){
                boring.push_back(i);
                for (int i:ke2[x])
                    if (ch[u[i]^v[i]^x]&&!--deg[u[i]^v[i]^x])
                        ve.push_back(u[i]^v[i]^x);
                C=1;
                ch[x]=1;
                x=y;
                break;
            }
        }
    }
}
void strain2(){
    while (!ve.empty()){
        C=1;
        int x=ve.back();
        ve.pop_back();
        ch[x]=1;
        for (int i:ke2[x]){
            int y=u[i]^v[i]^x;
            if (ch[y])
                continue;
            if (!--deg[y])
                ve.push_back(y);
        }
    }
}
variant <bool, vector <int>> find_journey(int N, int M, vector <int> U, vector <int> V) {
    n=N,m=M,u=U,v=V;
    for (int i=0;i<m;i++){
        ke[u[i]].push_back(i);
        ke2[v[i]].push_back(i);
        deg[u[i]]++;
    }
    for (int i=0;i<n;i++)
        if (!deg[i])
            ve.push_back(i);
    while (C){
        C=0;
        strain();
        strain2();
    }
    if (ch[x])
        return false;
    for (int i=0;i<n;i++){
        if (ch[i])
            continue;
        for (int j:ke[i])
            if (!ch[u[j]^v[j]^i])
                adj[i].push_back(j);
    }
    auto [ve,c]=dfs(x,adj[x][0]);
    auto [ve2,c2]=dfs(x,adj[x][1]);
    if (check(c,c2))
        fun=ve+c+rev(ve)+ve2+rev(c2)+rev(ve2);
    else
        fun=ve+c+rev(ve)+ve2+c2+rev(ve2)+ve+rev(c)+rev(ve)+ve2+rev(c2)+rev(ve2);
    return boring+fun+rev(boring);
}

Compilation message

islands.cpp: In function 'std::pair<std::vector<int>, std::vector<int> > dfs(int, int)':
islands.cpp:27:24: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   27 |     for (int i=pos[x];i<ve.size();i++)
      |                       ~^~~~~~~~~~
islands.cpp:29:21: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   29 |     while (ve.size()>pos[x])
      |            ~~~~~~~~~^~~~~~~
islands.cpp: In function 'bool check(std::vector<int>, std::vector<int>)':
islands.cpp:42:16: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   42 |     return (cnt==a.size());
      |             ~~~^~~~~~~~~~

Subtask #1
0.0 / 5.0

# Verdict Execution time Memory Grader output
1 Runtime error 18 ms 31580 KB Execution killed with signal 11
2 Halted 0 ms 0 KB -

Subtask #2
0.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 15964 KB Output is correct
2 Execution timed out 1054 ms 15708 KB Time limit exceeded
3 Halted 0 ms 0 KB -

Subtask #3
0.0 / 21.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 16220 KB Output is correct
2 Execution timed out 1065 ms 15708 KB Time limit exceeded
3 Halted 0 ms 0 KB -

Subtask #4
24.0 / 24.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 16216 KB Output is correct
2 Correct 6 ms 16220 KB Output is correct
3 Correct 31 ms 22356 KB Output is correct
4 Correct 35 ms 22484 KB Output is correct
5 Correct 8 ms 16216 KB Output is correct
6 Correct 6 ms 16220 KB Output is correct
7 Correct 5 ms 15964 KB Output is correct
8 Correct 6 ms 15840 KB Output is correct
9 Correct 5 ms 15964 KB Output is correct
10 Correct 7 ms 16220 KB Output is correct
11 Correct 5 ms 15964 KB Output is correct
12 Correct 5 ms 16220 KB Output is correct
13 Correct 7 ms 16220 KB Output is correct
14 Correct 6 ms 16220 KB Output is correct
15 Correct 6 ms 16220 KB Output is correct
16 Correct 6 ms 16220 KB Output is correct
17 Correct 4 ms 15708 KB Output is correct
18 Correct 6 ms 16220 KB Output is correct
19 Correct 6 ms 16132 KB Output is correct
20 Correct 32 ms 22876 KB Output is correct
21 Correct 36 ms 22400 KB Output is correct
22 Correct 5 ms 15964 KB Output is correct
23 Correct 5 ms 15708 KB Output is correct
24 Correct 5 ms 15708 KB Output is correct
25 Correct 5 ms 16164 KB Output is correct
26 Correct 5 ms 16220 KB Output is correct
27 Correct 35 ms 22876 KB Output is correct
28 Correct 36 ms 22992 KB Output is correct
29 Correct 4 ms 15704 KB Output is correct
30 Correct 35 ms 23384 KB Output is correct
31 Correct 5 ms 15960 KB Output is correct
32 Correct 36 ms 22864 KB Output is correct
33 Correct 31 ms 22620 KB Output is correct
34 Correct 21 ms 20060 KB Output is correct
35 Correct 6 ms 15960 KB Output is correct
36 Correct 31 ms 21852 KB Output is correct
37 Correct 35 ms 23372 KB Output is correct
38 Correct 5 ms 15704 KB Output is correct
39 Correct 29 ms 21592 KB Output is correct
40 Correct 5 ms 16216 KB Output is correct
41 Correct 34 ms 23132 KB Output is correct
42 Correct 34 ms 22864 KB Output is correct
43 Correct 5 ms 15908 KB Output is correct
44 Correct 5 ms 15964 KB Output is correct
45 Correct 5 ms 16220 KB Output is correct
46 Correct 18 ms 19548 KB Output is correct

Subtask #5
0.0 / 45.0

# Verdict Execution time Memory Grader output
1 Runtime error 18 ms 31580 KB Execution killed with signal 11
2 Halted 0 ms 0 KB -