Submission #543142

#	Time	Username	Problem	Language	Result	Execution time	Memory
543142		Olympia	Detecting Molecules (IOI16_molecules)	C++17	9 / 100	5 ms	308 KiB

molecules

#include <vector>
#include <algorithm>
#include <iostream>
#include <set>
#include <cmath>
#include <map>
#include <random>
#include <cassert>
#include <ctime>
#include <cstdlib>
#include <limits.h>
#include "molecules.h"

using namespace std;

int in_range (vector<int> &pref, int l, int r) {
    if (pref.back() < l) {
        return -1;
    }
    int tl = 0;
    int tr = pref.size() - 1;
    while (tl != tr) {
        int tm = (tl + tr)/2;
        if (pref[tm] >= l) {
            tr = tm;
        } else {
            tl = tm + 1;
        }
    }
    if (pref[tl] >= l && pref[tl] <= r) {
        return tl;
    }
    return -1;
}

vector<int> find_subset (int l, int r, vector<int> w) {
    for (int i = 0; i < w.size(); i++) {
        if (w[i] >= l && w[i] <= r) {
            return {i};
        }
    }
    vector<pair<int64_t,int>> vec;
    for (int i = 0; i < w.size(); i++) {
        vec.push_back({w[i], i});
    }
    int t = 1000;
    while (t--) {
        random_shuffle(vec.begin(), vec.end());
        vector<int> pref = {0};
        for (int i = 0; i < vec.size(); i++) {
            pref.push_back(pref.back() + vec[i].first);
        }
        for (int i = 0; i < pref.size(); i++) {
            if (in_range(pref, pref[i] + l, pref[i] + r) != -1) {
                int x = in_range(pref, pref[i] + l, pref[i] + r);
                vector<int> ans;
                for (int j = i; j <= x - 1; j++) {
                    ans.push_back(vec[j].second);
                }
                return ans;
            }
        }
    }
    return {};
}

void print (vector<int> v) {
    for (int i: v) {
        cout << i << ' ';
    }
    cout << '\n';
}


/*
int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    print(find_subset(15, 17, {6, 8, 8, 7}));
}


 */

Compilation message (stderr)

molecules.cpp: In function 'std::vector<int> find_subset(int, int, std::vector<int>)':
molecules.cpp:37:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   37 |     for (int i = 0; i < w.size(); i++) {
      |                     ~~^~~~~~~~~~
molecules.cpp:43:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   43 |     for (int i = 0; i < w.size(); i++) {
      |                     ~~^~~~~~~~~~
molecules.cpp:50:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<long int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   50 |         for (int i = 0; i < vec.size(); i++) {
      |                         ~~^~~~~~~~~~~~
molecules.cpp:53:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   53 |         for (int i = 0; i < pref.size(); i++) {
      |                         ~~^~~~~~~~~~~~~

• Subtask 1: 9 / 9
• Subtask 2: 0 / 10
• Subtask 3: 0 / 12
• Subtask 4: 0 / 15
• Subtask 5: 0 / 23
• Subtask 6: 0 / 31