Submission #825537

#	Time	Username	Problem	Language	Result	Execution time	Memory
825537		Trunkty	Teleporters (IOI08_teleporters)	C++14	100 / 100	350 ms	50736 KiB

teleporters

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

int n,m;
int pos[2000005],nex[2000005];
bool check[2000005];
vector<int> v;
int cnt,ans;

void dfs(int x){
    if(check[x]){
        return;
    }
    check[x] = true;
    cnt++;
    dfs(nex[x]);
}

signed main(){
    ios::sync_with_stdio(false);
	cin.tie(NULL);
    cin >> n >> m;
    for(int i=1;i<=n;i++){
        int a,b;
        cin >> a >> b;
        pos[a] = i;
        pos[b] = i+1e6;
    }
    int bef=0;
    for(int i=1;i<=2e6;i++){
        if(pos[i]){
            nex[bef] = pos[i];
            bef = pos[i];
        }
    }
    for(int i=1;i<=n;i++){
        swap(nex[i],nex[i+1000000]);
    }
    dfs(0);
    ans = cnt-1LL;
    for(int i=1;i<=n;i++){
        if(!check[i]){
            cnt = 0;
            dfs(i);
            v.push_back(cnt);
        }
        if(!check[i+1000000]){
            cnt = 0;
            dfs(i+1000000);
            v.push_back(cnt);
        }
    }
    sort(v.begin(),v.end(),greater<int>());
    if(v.size()>=m){
        for(int i=0;i<=m-1;i++){
            ans += v[i];
        }
        ans += 2LL*m;
    }
    else{
        for(int i=0;i<v.size();i++){
            ans += v[i];
        }
        ans += 2LL*(v.size());
        ans += ((m-v.size())/2LL)*4LL;
        ans += (m-v.size())%2LL;
    }
    cout << ans << "\n";
    return 0;
}

Compilation message (stderr)

teleporters.cpp: In function 'int main()':
teleporters.cpp:56:16: warning: comparison of integer expressions of different signedness: 'std::vector<long long int>::size_type' {aka 'long unsigned int'} and 'll' {aka 'long long int'} [-Wsign-compare]
   56 |     if(v.size()>=m){
      |        ~~~~~~~~^~~
teleporters.cpp:63:22: 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]
   63 |         for(int i=0;i<v.size();i++){
      |                     ~^~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 5 / 5
• Subtask 3: 5 / 5
• Subtask 4: 5 / 5
• Subtask 5: 5 / 5
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• Subtask 20: 5 / 5