Submission #54075

#	Time	Username	Problem	Language	Result	Execution time	Memory
54075		imeimi2000	Teleporters (IOI08_teleporters)	C++17	90 / 100	1082 ms	26040 KiB

teleporters

#include <iostream>
#include <algorithm>
#include <vector>
#include <queue>
#include <deque>
#include <set>
#include <map>
#include <unordered_map>
#include <functional>
#include <cstring>
#include <cmath>
#include <ctime>
#include <cstdlib>

using namespace std;
typedef long long llong;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<llong, llong> pll;

int n, m;
int s[1000000];
int e[1000000];
int comp[2000000];
int to[2000000];
bool visited[2000001];
int arr[2000000];

int find(int x) {
    int s = 0, e = n << 1;
    while (s <= e) {
        int m = (s + e) / 2;
        if (comp[m] == x) return m;
        if (comp[m] < x) s = m + 1;
        else e = m - 1;
    }
}

int main() {
    ios_base::sync_with_stdio(false); cin.tie(0);
    cin >> n >> m;
    for (int i = 0; i < n; ++i) {
        cin >> s[i] >> e[i];
        comp[i << 1 | 0] = s[i];
        comp[i << 1 | 1] = e[i];
    }
    comp[n << 1] = 0;
    sort(comp, comp + (n << 1 | 1));
    for (int i = 0; i < n; ++i) {
        s[i] = find(s[i]);
        e[i] = find(e[i]);
        to[s[i]] = e[i];
        to[e[i]] = s[i];
    }
    visited[n << 1] = 1;
    int sz = -1;
    for (int i = 0; i < (n << 1); ++i) {
        if (visited[i]) continue;
        int x = to[i + 1];
        visited[i] = 1;
        int s = 1;
        while (!visited[x]) {
            visited[x] = 1;
            x = to[x + 1];
            ++s;
        }
        if (sz != -1) ++arr[s];
        else sz = s;
    }
    for (int i = 2 * n - 1; i > 0 && m > 0; --i) {
        while (arr[i] > 0 && m > 0) {
            sz += i + 2;
            --arr[i];
            --m;
        }
    }
    printf("%d\n", sz + ((m >> 1) << 2) + (m & 1));
    
	return 0;
}

Compilation message (stderr)

teleporters.cpp: In function 'int find(int)':
teleporters.cpp:37:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^

• Subtask 1: 5 / 5
• Subtask 2: 5 / 5
• Subtask 3: 5 / 5
• Subtask 4: 5 / 5
• Subtask 5: 5 / 5
• Subtask 6: 5 / 5
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• Subtask 15: 5 / 5
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• Subtask 19: 0 / 5
• Subtask 20: 0 / 5