Submission #1135701

#	Time	Username	Problem	Language	Result	Execution time	Memory
1135701		Aviansh	Izlet (COI19_izlet)	C++20	100 / 100	1029 ms	36804 KiB

izlet

#include <bits/stdc++.h>

using namespace std;

struct dsu{
    vector<int>root;
    vector<int>siz;
    vector<set<int>>childs;
    dsu(int n){
        root=vector<int>(n);
        siz=vector<int>(n,1);
        childs=vector<set<int>>(n);
        iota(root.begin(),root.end(),0);
        for(int i = 0;i<n;i++){
            childs[i].insert(i);
        }
    }

    bool unite(int x, int y){
        x=findRoot(x);
        y=findRoot(y);
        if(x==y){
            return 0;
        }
        if(siz[x]<siz[y]){
            swap(x,y);
        }
        root[y]=x;
        siz[x]+=siz[y];
        for(int i : childs[y]){
            childs[x].insert(i);
        }
        return 1;
    }

    int findRoot(int x){
        if(x==root[x]){
            return x;
        }
        return root[x]=findRoot(root[x]);
    }

};

const int maxn=3e3+5;

vector<int>path;
dsu ds(maxn);

void dfs(int st, int p, int o, vector<int>(&g)[],int grid[][maxn]){
    path.push_back(st);
    if(st!=o&&grid[o][st]==grid[o][p]){
        int lo = 0;
        int hi = path.size()-1;
        while(lo<hi){
            int mid = (lo+hi)/2;
            if(grid[path[mid]][st]==grid[path[mid]][p]){
                lo=mid+1;
            }
            else{
                hi=mid;
            }
        }
        ds.unite(path[lo-1],st);
    }
    for(int i : g[st]){
        if(i==p)
            continue;
        dfs(i,st,o,g,grid);
    }
    path.pop_back();
}

signed main(){
    ios::sync_with_stdio(0);
    cin.tie(0);
    int s;
    cin >> s;
    int n;
    cin >> n;
    int grid[n][maxn];
    vector<int>g[n];
    for(int i = 0;i<n;i++){
        for(int j = 0;j<n;j++){
            cin >> grid[i][j];
            if(grid[i][j]==1){
                if(ds.unite(i,j)){
                    g[i].push_back(j);
                    g[j].push_back(i);
                }
            }
        }
    }
    for(int i = 0;i<n;i++){
        for(int j = 0;j<n;j++){
            if(grid[i][j]==2){
                if(ds.unite(i,j)){
                    g[i].push_back(j);
                    g[j].push_back(i);
                }
            }
        }
    }
    ds=dsu(n);
    vector<int>path;
    set<int>vis;
    for(int i = 0;i<n;i++){
        dfs(i,-1,i,g,grid);
    }
    for(int i = 0;i<n;i++){
        cout << ds.findRoot(i)+1 << " ";
    }
    cout << "\n";
    for(int i = 0;i<n;i++){
        for(int j : g[i]){
            if(j>i){
                cout << i+1 << " " << j+1 << "\n";
            }
        }
    }
    return 0;
}

• Subtask 1: 18 / 18
• Subtask 2: 25 / 25
• Subtask 3: 57 / 57