Submission #197914

#	Time	Username	Problem	Language	Result	Execution time	Memory
197914		SamAnd	Teleporters (IOI08_teleporters)	C++17	75 / 100	1030 ms	65540 KiB

teleporters

#include <bits/stdc++.h>
using namespace std;
const int N = 2000006;
struct ban
{
    int x, i;
    ban(){}
    ban(int x, int i)
    {
        this->x = x;
        this->i = i;
    }
};
bool operator<(const ban& a, const ban& b)
{
    return a.x < b.x;
}

int n, m;
pair<int, int> b[N];

vector<int> v;

vector<int> a[N];

bool c[N];
int q;
void dfs(int x)
{
    c[x] = true;
    ++q;
    for (int i = 0; i < a[x].size(); ++i)
    {
        int h = a[x][i];
        if (!c[h])
            dfs(h);
    }
}

priority_queue<int> qq;
int main()
{
    #ifdef SOMETHING
    freopen("input.txt", "r", stdin);
    #endif // SOMETHING
    scanf("%d%d", &n, &m);
    for (int i = 1; i <= n; ++i)
    {
        scanf("%d%d", &b[i].first, &b[i].second);
        v.push_back(b[i].first);
        v.push_back(b[i].second);
    }
    sort(v.begin(), v.end());
    for (int i = 1; i <= n; ++i)
    {
        b[i].first = lower_bound(v.begin(), v.end(), b[i].first) - v.begin() + 1;
        b[i].second = lower_bound(v.begin(), v.end(), b[i].second) - v.begin() + 1;
    }
    for (int i = 1; i <= n; ++i)
    {
        a[b[i].first - 1].push_back(b[i].second);
        a[b[i].second - 1].push_back(b[i].first);
    }
    int ans = 0;
    q = 0;
    dfs(0);
    ans += (q - 1);
    for (int i = 1; i <= n * 2; ++i)
    {
        if (!c[i])
        {
            q = 0;
            dfs(i);
            qq.push(q);
        }
    }
    while (m--)
    {
        if (qq.empty())
        {
            ++ans;
            qq.push(1);
        }
        else
        {
            ans += (qq.top() + 2);
            qq.pop();
        }
    }
    printf("%d\n", ans);
    return 0;
}

Compilation message (stderr)

teleporters.cpp: In function 'void dfs(int)':
teleporters.cpp:32:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (int i = 0; i < a[x].size(); ++i)
                     ~~^~~~~~~~~~~~~
teleporters.cpp: In function 'int main()':
teleporters.cpp:46:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d%d", &n, &m);
     ~~~~~^~~~~~~~~~~~~~~~
teleporters.cpp:49:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d%d", &b[i].first, &b[i].second);
         ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 5 / 5
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