Submission #749928

#	Time	Username	Problem	Language	Result	Execution time	Memory
749928		Trunkty	Matching (COCI20_matching)	C++14	5 / 110	5 ms	7384 KiB

matching

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define int ll

int n;
vector<int> row[100005],col[100005];
int root[100005];
vector<int> vals[100005];
vector<vector<int>> ans;

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

void domerge(int a, int b){
    int x = findroot(a), y = findroot(b);
    if(x==y){
        return;
    }
    else{
        if(vals[x].size()<vals[y].size()){
            swap(x,y);
            swap(a,b);
        }
        if(vals[x][0]==a){
            reverse(vals[x].begin(),vals[x].end());
        }
        if(vals[y][0]!=b){
            reverse(vals[y].begin(),vals[y].end());
        }
        for(int i:vals[y]){
            vals[x].push_back(i);
        }
        vals[y].clear();
        root[y] = x;
    }
}

signed main(){
    ios::sync_with_stdio(false);
    cin.tie(NULL);
    cin >> n;
    for(int i=1;i<=n;i++){
        root[i] = i;
        vals[i].push_back(i);
    }
    for(int i=1;i<=n;i++){
        int a,b;
        cin >> a >> b;
        row[a].push_back(i);
        col[b].push_back(i);
    }
    for(int i=1;i<=1e5;i++){
        if(row[i].size()==2){
            domerge(row[i][0],row[i][1]);
        }
    }
    for(int i=1;i<=1e5;i++){
        if(col[i].size()==2){
            domerge(col[i][0],col[i][1]);
        }
    }
    for(int i=1;i<=n;i++){
        if(root[i]==i){
            if(vals[i].size()%2){
                cout << "NE" << "\n";
                return 0;
            }
            for(int j=0;j<vals[i].size();j+=2){
                ans.push_back({vals[i][j],vals[i][j+1]});
            }
        }
    }
    cout << "DA" << "\n";
    for(vector<int> i:ans){
        cout << i[0] << " " << i[1] << "\n";
    }
    return 0;
}

Compilation message (stderr)

matching.cpp: In function 'int main()':
matching.cpp:73:26: warning: comparison of integer expressions of different signedness: 'll' {aka 'long long int'} and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   73 |             for(int j=0;j<vals[i].size();j+=2){
      |                         ~^~~~~~~~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 0 / 6
• Subtask 3: 0 / 7
• Subtask 4: 0 / 40
• Subtask 5: 0 / 52