Submission #1135210

#	Time	Username	Problem	Language	Result	Execution time	Memory
1135210		nightfal	Toy Train (IOI17_train)	C++20	27 / 100	175 ms	98648 KiB

train

#include <iostream>
#include <vector>
#include <queue>
#include <cstdio>
#include <cassert>
#include <algorithm>

using namespace std;

void printAdjMatrix(vector<vector<int>>& adjM) {
    int n = adjM.size();
    for(int i=0; i<n; i++) {
        printf("%d:",i);
        for(int elem: adjM[i])
            printf(" %d",elem);
        printf("\n");
    }
}
void printAdjList(vector<vector<int>>& adjL) {
    int n = adjL.size();
    for(int i=0; i<n; i++) {
        printf("%d:",i);
        for(int elem: adjL[i])
            printf(" %d", elem);
        printf("\n");
    }
}
void printDegree(vector<int>& Deg) {
    int n = Deg.size();
    for(int i=0; i<n; i++) printf("Deg[%d]=%d ",i,Deg[i]);
    printf("\n");
}

bool isSubtask1(vector<int>& u, vector<int>& v) {
    int m = u.size();
    for(int i=0; i<m; i++)
        if (v[i]!=u[i] && v[i]!=u[i]+1) return false;
    return true;
}
bool isSubtask2(const int n) {return n <= 15;}
bool isSubtask3(const vector<int>& a) {return find(a.begin(),a.end(),0)==a.end();}
bool isSubtask4(const vector<int>& a) {return find(a.begin(),a.end(),1)==a.end();}

bool dfs(int now, int dest, vector<int>& a, vector<int>& r, vector<vector<int>>& adjL, vector<int>& dis, vector<int>& ans) {
    // printf("now:%d, dest:%d, dis[%d]=%d, r[%d]=%d, ans[%d]=%d\n",now,dest,now,(int) dis[now],now,r[now],now,ans[now]);
    if (now==dest) return true;
    if (dis[now]) return false;
    else dis[now] = 1;
    if (a[now]) {
        for(int i=0; i<adjL[now].size(); i++)
            if(dfs(adjL[now][i],dest,a,r,adjL,dis,ans)) {ans[now]=1; break;}
    }
    else {
        int i;
        for(i=0; i<adjL[now].size(); i++)
            if(!dfs(adjL[now][i],dest,a,r,adjL,dis,ans)) break;
        if (i==adjL[now].size()) ans[now] = 1;
    }
    if (ans[now]) printf("win %d \n",now);
    return ans[now];
}
void checkNeighbor(int now, vector<int>& a, vector<vector<int>>& adjL, vector<int>& ans) {
    if (a[now]) {
        for(int i=0; i<adjL[now].size(); i++)
            if(ans[adjL[now][i]]) ans[now]=1;
    }
    else {
        int i;
        for(i=0; i<adjL[now].size(); i++)
            if(!ans[adjL[now][i]]) break;
        if (i==adjL[now].size()) ans[now] = 1;
    }
}
bool dfs3(const int now, const int dest, const vector<vector<int>>& adjL, vector<int>& visit) {
    if (visit[now]) return false;
    visit[now] = 1;
    if (now==dest) return true;
    for(int i=0; i<adjL[now].size(); i++) 
        if(dfs3(adjL[now][i],dest,adjL,visit)) return true; 
    return false;
}
vector<int> fulltask(vector<int>& a, vector<int>& r, vector<int>& u, vector<int>& v) {
    int n=a.size(), m=u.size();
    vector<vector<int>> adjL(n+1), adjLRev(n+1);
    for(int i=0; i<m; i++) {adjL[u[i]].push_back(v[i]); adjLRev[v[i]].push_back(u[i]);}

    vector<int> ans(n), cnt(n);
    queue<int> q;
    bool update=true;
    while(update) { 
        for(int j=0; j<n; j++) if (r[j]==1) q.push(j);
        cnt.assign(n,0); ans.assign(n,0);
        while(!q.empty()) {
            int node = q.front(); q.pop(); 
            for(int elem: adjLRev[node]) {
                cnt[elem]++;
                if (a[elem] && cnt[elem]==1 || !a[elem] && cnt[elem]==adjL[elem].size()) {
                    ans[elem]=1; 
                    if(!r[elem]) q.push(elem);
                }
            }
        }
        update = false;
        for(int j=0; j<n; j++) if(r[j]&&!ans[j]) {r[j] = 0; update=true;}
        if (!update) return ans;
    }
}
vector<int> subtask4(vector<int>& a, vector<int>& r, vector<int>& u, vector<int>& v) {
    int n=a.size(), m=u.size();
    vector<vector<int>> adjL(n+1), adjLRev(n+1);
    for(int i=0; i<m; i++) {adjL[u[i]].push_back(v[i]); adjLRev[v[i]].push_back(u[i]);}

    vector<int> cnt(n), ans(n);
    queue<int> q;
    bool update=true;
    while(update) { 
        for(int j=0; j<n; j++) if (r[j]==1) q.push(j);
        cnt.assign(n,0); ans.assign(n,0);
        while(!q.empty()) {
            int node = q.front(); q.pop(); 
            for(int elem: adjLRev[node]) 
                if (++cnt[elem]==adjL[elem].size()) {
                    ans[elem]=1; 
                    if(!r[elem]) q.push(elem);
                }
        }
        update=false;
        for(int j=0; j<n; j++) if(r[j]&&!ans[j]) {r[j] = 0; update=true;}

        if (!update) return ans;
    }
}
vector<int> subtask3(vector<int>& a, vector<int>& r, vector<int>& u, vector<int>& v) {
    int n=a.size(), m=u.size();
    vector<vector<int>> adjL(n+1), adjLRev(n);

    for(int i=0; i<m; i++) {adjL[u[i]].push_back(v[i]); adjLRev[v[i]].push_back(u[i]);}

    vector<int> ans(n), visit(n+1);
    for(int i=0; i<n; i++) {
        if(r[i]) {
            visit.assign(n+1,0);
            adjL[n] = adjL[i];
            if (dfs3(n,i,adjL,visit)) ans[i]=1;
        }
    }
    // convert to dfs recursion (?)
    queue<int> q;
    for(int i=0; i<n; i++) if(ans[i]) q.push(i);
    while(!q.empty()) {
        int node = q.front(); q.pop(); 
        for(int elem: adjLRev[node])
            if (ans[elem]==0) {ans[elem]=1; q.push(elem);} 
    }
    return ans;
}
vector<int> subtask2(vector<int>& a, vector<int>& r, vector<int>& u, vector<int>& v) {
    int n=a.size(), m=u.size();
    // queue<int> q;
    vector<vector<int>> adjL(n), adjLRev(n), adjM(n,vector<int>(n));
    vector<int> inDeg(n), outDeg(n);

    for(int i=0; i<m; i++) {
        adjL[u[i]].push_back(v[i]); adjLRev[v[i]].push_back(u[i]);
        adjM[u[i]][v[i]] = 1;
        inDeg[v[i]]++; outDeg[u[i]]++;
    }
    for(auto& list: adjL) sort(list.begin(),list.end());
    for(auto& list: adjLRev) sort(list.begin(),list.end());

    // printf("Adjacency Matrix\n"); printAdjMatrix(adjM);
    // printf("Adjacency List\n"); printAdjList(adjL);
    // printf("Adjacency List Reverse\n"); printAdjList(adjLRev);

    // printf("outDegree\n"); printDegree(outDeg);
    // printf("inDegree\n"); printDegree(inDeg);

    vector<int> ans(n);

    for(int i=0; i<n; i++) 
        if(r[i] && !ans[i]) {
            vector<int> dis(n); int j;
            dis[i] = 1;
            if(a[i]) {
                for(j=0; j<adjL[i].size(); j++) 
                    if(dfs(adjL[i][j],i,a,r,adjL,dis,ans)) break;
                if (j<adjL[i].size()) {ans[i] = 1;} // printf("ans[%d]=%d\n",i,ans[i]);}
            }
            else {
                for(j=0; j<adjL[i].size(); j++) 
                    if(!dfs(adjL[i][j],i,a,r,adjL,dis,ans)) break;
                if (j==adjL[i].size()) {ans[i] = 1;} //  printf("ans[%d]=%d\n",i,ans[i]);}
            }
            // if (ans[i]) printf("win %d \n",i);
        }

    for(int i=0; i<n; i++)
        for(int j=0; j<n; j++)
            if (ans[j]==0) checkNeighbor(j,a,adjL,ans);
       
    return ans;
}
vector<int> subtask1(vector<int>& a, vector<int>& r, vector<int>& u, vector<int>& v) {
    int n = a.size(), m = u.size();
    vector<int> ans(n);
    vector<vector<int>> adj(n,vector<int>(n));
    for(int i=0; i<m; i++) adj[u[i]][v[i]] = 1;
    ans[n-1]=r[n-1];
    for(int i=n-2; i>=0; i--)
        if (a[i]) {ans[i] = adj[i][i] && r[i] || adj[i][i+1] && ans[i+1];}
        else {ans[i] = (adj[i][i]==0 || r[i]) && (adj[i][i+1]==0 || ans[i+1]);}
    return ans;
}

vector<int> who_wins(vector<int> a, vector<int> r, vector<int> u, vector<int> v) {
    // return fulltask(a,r,u,v);
    if (isSubtask4(a)) return subtask4(a,r,u,v);
    if (isSubtask3(a)) return subtask3(a,r,u,v);
    if (isSubtask1(u,v)) return subtask1(a,r,u,v);
    return subtask1(a,r,u,v);

    int n = a.size(), m = u.size();
    vector<vector<int>> adj(n);

    for(int i=0; i<m; i++) adj[u[i]].push_back(v[i]);
    for(int i=0; i<n; i++) sort(adj[i].begin(),adj[i].end());


    // if (isSubtask2(n)) return subtask2(a,r,u,v);
    // for(int i=0; i<n; i++) {
    //     cout << i << ": ";
    //     for (const int elem: adj[i])
    //         cout << elem << " ";
    //     cout << endl;
    // }

}

Compilation message (stderr)

train.cpp: In function 'std::vector<int> fulltask(std::vector<int>&, std::vector<int>&, std::vector<int>&, std::vector<int>&)':
train.cpp:107:1: warning: control reaches end of non-void function [-Wreturn-type]
  107 | }
      | ^
train.cpp: In function 'std::vector<int> subtask4(std::vector<int>&, std::vector<int>&, std::vector<int>&, std::vector<int>&)':
train.cpp:132:1: warning: control reaches end of non-void function [-Wreturn-type]
  132 | }
      | ^

• Subtask 1: 5 / 5
• Subtask 2: 0 / 10
• Subtask 3: 11 / 11
• Subtask 4: 11 / 11
• Subtask 5: 0 / 12
• Subtask 6: 0 / 51