Submission #239195

#	Time	Username	Problem	Language	Result	Execution time	Memory
239195		osaaateiasavtnl	Teleporters (IOI08_teleporters)	C++14	75 / 100	940 ms	40308 KiB

teleporters

#include<bits/stdc++.h>
using namespace std;
#define ii pair <int, int>
#define app push_back
#define all(a) a.begin(), a.end()
#define bp __builtin_popcountll
#define ll long long
#define mp make_pair
#define f first
#define s second
#define Time (double)clock()/CLOCKS_PER_SEC

const int C = 2e6+7;
int who[C];

signed main() {
    #ifdef HOME
    freopen("input.txt", "r", stdin);
    #else
    #define endl '\n'
    ios_base::sync_with_stdio(0); cin.tie(0);
    #endif

    int n, m;
    cin >> n >> m;

    vector <ii> a(n);
    vector <int> c = {0, 2 * 1000 * 1000 + 1};

    for (int i = 0; i < n; ++i) {
        cin >> a[i].f >> a[i].s;
        c.app(a[i].f);
        c.app(a[i].s);
        who[a[i].f] = i;
        who[a[i].s] = i;
    }   
    sort(all(c));

    int sz = c.size() - 1;
    vector <int> to(sz, -1);
    for (int i = 0; i + 2 < c.size(); ++i) {
        int u = who[c[i+1]];
        int x = a[u].f^a[u].s^c[i+1];
        to[i] = lower_bound(all(c), x) - c.begin();
    }   

    int ans = 0;

    vector <int> len;
    vector <bool> used(sz);
    for (int i = 0; i < sz; ++i) {
        if (!used[i]) {
            int u = i;
            int l = 0;
            while (u != -1 && !used[u]) {
                used[u] = 1;
                ++l;
                u = to[u];
            }

            if (u == -1) {
                ans += l;
            }   
            else {
                len.app(l);
            }
        }   
    }

    sort(all(len));
    reverse(all(len));
    for (int i = 0; i < min(m, (int)len.size()); ++i) {
        ans += len[i];
    }   
    ans += 2 * m - 1;
    cout << ans << endl;
}

Compilation message (stderr)

teleporters.cpp: In function 'int main()':
teleporters.cpp:41:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (int i = 0; i + 2 < c.size(); ++i) {
                     ~~~~~~^~~~~~~~~~

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