Submission #883916

#	Time	Username	Problem	Language	Result	Execution time	Memory
883916		macneil	Let's Win the Election (JOI22_ho_t3)	C++17	28 / 100	242 ms	604 KiB

Main

//cf meowcneil; t.me/macneilbot
 
#include <iostream>
#include <vector>
#include <cmath>
#include <algorithm>
#include <string>
#include <bitset>
#include <iterator>
#include <iomanip>
#include <map>
#include <set>
#include <unordered_map>
#include <unordered_set>
#include <ctime>
#include <deque>
#include <queue>
#include <stack>
#include <random>
#include <cassert>
 
using namespace std;
 
#define int long long
#define pb push_back
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define f(a) for(int i = 0; i<a; ++i)
 
typedef long long ll;
typedef unsigned long long ull;
typedef double ld;
typedef string str;
typedef vector<str> vestr;
typedef vector<int> vei;
typedef vector<vector<int>> veve;
 
mt19937 rnd(1329);
 
const int NUM = 2e4;
 
int k;
 
bool flip(int a, int b) {
    return ((rnd() % (a + b))) < a;
}
 
ld cost(vector<int> &a, vector<int> &b, vector<int> &inb, vector<int> &ord1) {
    int n = a.size();
    ld ans = 0;
    vector<int> auu;
    for (int i = 0; i < n; ++i) {
        if (inb[i]) {
            auu.push_back(i);
        }
    }
    sort(all(auu), [&](int i, int j){ return b[i] < b[j];});
    for (int i = 0; i < auu.size(); ++i) {
        ans += (ld)(b[auu[i]]) / (i + 1);
    }
    int ctt = auu.size();
    for (auto i : ord1) {
        if (ctt == k) break;
        if (!inb[i]) {
            ans += (ld)a[i] / (auu.size() + 1);
            ctt++;
        }
    }
    return ans;
}
 
 
void solve() {
    int n;
    cin >> n >> k;
    vector<int> a(n), b(n);
    for (int i = 0; i < n; ++i) cin >> a[i] >> b[i];
    // for (int i = 0; i < n; ++i) if (b[i] == -1) b[i] = 1e14;
    vector<int> ord1(n), ord2(n);
    iota(all(ord1), 0);
    iota(all(ord2), 0);
    sort(all(ord1), [&](int i, int j){
        return a[i] < a[j];
    });
    sort(all(ord2), [&](int i, int j){
        if (b[i] == b[j]) return a[i] > a[j];
        return b[i] < b[j];
    });
    vector<int> notminusone;
    for (int i = 0; i < n; ++i) if (b[i] != -1) notminusone.push_back(i);
    ld ans = 0;
    for (int i = 0; i < k; ++i) ans += a[ord1[i]];
    if (notminusone.size() == 0) {
        cout << ans;
        return;
    }
    vector<int> inb(n);
    ld prevans = ans;
    for (int i = 0; i < NUM; ++i) {
        vector<int> tt;
        for (int j = 0; j < rnd() % 10 + 1; ++j) {
            tt.push_back(rnd() % (notminusone.size()));
            inb[notminusone[tt[j]]] ^= 1;
        }
        if (cost(a, b, inb, ord1) < prevans) {
            prevans = cost(a, b, inb, ord1);
            ans = min(ans, prevans);
        }
        else {
            for (auto e : tt) inb[notminusone[e]] ^= 1;
        }
    }
    cout << ans << '\n';
}
 
signed main() {
    int tc = 1;
    cout << fixed << setprecision(15);
#ifdef LOCAL
    freopen("in.txt", "r", stdin);
    freopen("out.txt", "w", stdout);
    cin >> tc;
#else
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
    // cin >> tc;
#endif
    for (int t = 1; t <= tc; t++) {
        // cout << "Case #" << t  << ": ";
        solve();
    }
}

Compilation message (stderr)

Main.cpp: In function 'bool flip(long long int, long long int)':
Main.cpp:45:32: warning: comparison of integer expressions of different signedness: 'long long unsigned int' and 'long long int' [-Wsign-compare]
   45 |     return ((rnd() % (a + b))) < a;
      |            ~~~~~~~~~~~~~~~~~~~~^~~
Main.cpp: In function 'ld cost(std::vector<long long int>&, std::vector<long long int>&, std::vector<long long int>&, std::vector<long long int>&)':
Main.cpp:58:23: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   58 |     for (int i = 0; i < auu.size(); ++i) {
      |                     ~~^~~~~~~~~~~~
Main.cpp: In function 'void solve()':
Main.cpp:101:27: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::mersenne_twister_engine<long unsigned int, 32, 624, 397, 31, 2567483615, 11, 4294967295, 7, 2636928640, 15, 4022730752, 18, 1812433253>::result_type' {aka 'long unsigned int'} [-Wsign-compare]
  101 |         for (int j = 0; j < rnd() % 10 + 1; ++j) {
      |                         ~~^~~~~~~~~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 0 / 5
• Subtask 3: 11 / 11
• Subtask 4: 12 / 12
• Subtask 5: 0 / 33
• Subtask 6: 0 / 11
• Subtask 7: 0 / 23