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Submission #907268

# Submission time Handle Problem Language Result Execution time Memory
907268 2024-01-15T10:33:10 Z abcvuitunggio Thousands Islands (IOI22_islands) C++17
34 / 100
 37 ms 23380 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;
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 (!--deg[u[i]^v[i]^x])
                        ve.push_back(u[i]^v[i]^x);
                ch[x]=1;
                x=y;
                break;
            }
        }
    }
}
void strain2(){
    while (!ve.empty()){
        int x=ve.back();
        ve.pop_back();
        ch[x]=1;
        for (int i:ke2[x]){
            int y=u[i]^v[i]^x;
            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 (true){
        int tmp=x;
        strain();
        strain2();
        if (ch[x])
            return false;
        if (x==tmp)
            break;
    }
    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:26:24: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   26 |     for (int i=pos[x];i<ve.size();i++)
      |                       ~^~~~~~~~~~
islands.cpp:28:21: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   28 |     while (ve.size()>pos[x])
      |            ~~~~~~~~~^~~~~~~
islands.cpp: In function 'bool check(std::vector<int>, std::vector<int>)':
islands.cpp:41:16: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   41 |     return (cnt==a.size());
      |             ~~~^~~~~~~~~~

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 15704 KB Output is correct
2 Correct 5 ms 15964 KB Output is correct
3 Correct 4 ms 15832 KB Output is correct
4 Correct 6 ms 15708 KB Output is correct
5 Correct 6 ms 15960 KB Output is correct
6 Correct 5 ms 15964 KB Output is correct
7 Correct 33 ms 23188 KB Output is correct

Subtask #2
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 15960 KB Output is correct
2 Correct 4 ms 15708 KB Output is correct
3 Correct 4 ms 16000 KB Output is correct
4 Correct 5 ms 15964 KB Output is correct
5 Correct 5 ms 15964 KB Output is correct
6 Correct 30 ms 22240 KB Output is correct

Subtask #3
0.0 / 21.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 16216 KB Output is correct
2 Correct 5 ms 15708 KB Output is correct
3 Correct 5 ms 15708 KB Output is correct
4 Correct 5 ms 15960 KB Output is correct
5 Correct 6 ms 15964 KB Output is correct
6 Correct 5 ms 15960 KB Output is correct
7 Correct 5 ms 15704 KB Output is correct
8 Incorrect 5 ms 15704 KB Output isn't correct
9 Halted 0 ms 0 KB -

Subtask #4
24.0 / 24.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 15964 KB Output is correct
2 Correct 6 ms 16216 KB Output is correct
3 Correct 35 ms 22352 KB Output is correct
4 Correct 32 ms 22480 KB Output is correct
5 Correct 7 ms 16220 KB Output is correct
6 Correct 7 ms 16140 KB Output is correct
7 Correct 4 ms 16164 KB Output is correct
8 Correct 6 ms 16220 KB Output is correct
9 Correct 5 ms 15964 KB Output is correct
10 Correct 8 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 6 ms 16096 KB Output is correct
14 Correct 5 ms 16220 KB Output is correct
15 Correct 6 ms 16220 KB Output is correct
16 Correct 5 ms 16216 KB Output is correct
17 Correct 4 ms 15708 KB Output is correct
18 Correct 6 ms 16220 KB Output is correct
19 Correct 5 ms 15964 KB Output is correct
20 Correct 32 ms 22864 KB Output is correct
21 Correct 32 ms 22392 KB Output is correct
22 Correct 5 ms 15964 KB Output is correct
23 Correct 6 ms 15708 KB Output is correct
24 Correct 6 ms 15704 KB Output is correct
25 Correct 6 ms 15960 KB Output is correct
26 Correct 6 ms 16220 KB Output is correct
27 Correct 35 ms 22868 KB Output is correct
28 Correct 34 ms 22872 KB Output is correct
29 Correct 5 ms 15704 KB Output is correct
30 Correct 36 ms 23328 KB Output is correct
31 Correct 5 ms 15960 KB Output is correct
32 Correct 37 ms 22864 KB Output is correct
33 Correct 33 ms 22872 KB Output is correct
34 Correct 21 ms 19988 KB Output is correct
35 Correct 5 ms 15964 KB Output is correct
36 Correct 30 ms 21732 KB Output is correct
37 Correct 35 ms 23380 KB Output is correct
38 Correct 5 ms 15708 KB Output is correct
39 Correct 33 ms 21408 KB Output is correct
40 Correct 6 ms 16220 KB Output is correct
41 Correct 34 ms 23308 KB Output is correct
42 Correct 35 ms 22868 KB Output is correct
43 Correct 5 ms 15708 KB Output is correct
44 Correct 5 ms 15964 KB Output is correct
45 Correct 5 ms 16104 KB Output is correct
46 Correct 21 ms 19548 KB Output is correct

Subtask #5
0.0 / 45.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 15704 KB Output is correct
2 Correct 5 ms 15964 KB Output is correct
3 Correct 4 ms 15832 KB Output is correct
4 Correct 6 ms 15708 KB Output is correct
5 Correct 6 ms 15960 KB Output is correct
6 Correct 5 ms 15964 KB Output is correct
7 Correct 33 ms 23188 KB Output is correct
8 Correct 5 ms 15960 KB Output is correct
9 Correct 4 ms 15708 KB Output is correct
10 Correct 4 ms 16000 KB Output is correct
11 Correct 5 ms 15964 KB Output is correct
12 Correct 5 ms 15964 KB Output is correct
13 Correct 30 ms 22240 KB Output is correct
14 Correct 6 ms 16216 KB Output is correct
15 Correct 5 ms 15708 KB Output is correct
16 Correct 5 ms 15708 KB Output is correct
17 Correct 5 ms 15960 KB Output is correct
18 Correct 6 ms 15964 KB Output is correct
19 Correct 5 ms 15960 KB Output is correct
20 Correct 5 ms 15704 KB Output is correct
21 Incorrect 5 ms 15704 KB Output isn't correct
22 Halted 0 ms 0 KB -