Submission #785655

#	Time	Username	Problem	Language	Result	Execution time	Memory
785655		Boas	Detecting Molecules (IOI16_molecules)	C++17	9 / 100	1077 ms	308 KiB

molecules

#include "molecules.h"

using namespace std;
#include <bits/stdc++.h>


#define MAX_N 200001
#define ALL(x) x.begin(), x.end()

typedef vector<int> vi;

int L{};
int U{};

int n{};

vi mols;

vi addMolecule(const int &i, const int &w, const unordered_set<int> &used)
{
    if (i >= mols.size())
    {
        return {};
    }
    int nw = w + mols[i];
    if (nw > U)
    {
        return addMolecule(i + 1, w, used);
    }
    if (nw >= L)
    {
        vi solution(ALL(used));
        solution.push_back(i);
        return solution;
    }
    auto dontAdd = addMolecule(i + 1, w, used);
    if (dontAdd.size() > 0)
        return dontAdd;
    unordered_set<int> newUsed(used);
    newUsed.insert(i);
    auto add = addMolecule(i + 1, nw, newUsed);
    if (add.size() > 0)
        return add;
    return {};
}

vi find_subset(int l, int u, vi w)
{
    n = w.size();
    bool allSame = true;
    for (int i = 1; i < n; i++)
    {
        if (w[i] != w[i - 1])
        {
            allSame = false;
            break;
        }
    }
    if (allSame)
    {
        int s = 0;
        int i = 0;
        vi res;
        for (int i = 0; i < n; i++)
        {
            s += w[0];
            res.push_back(i);
            if (s > u)
                break;
            if (s >= l)
                return res;
        }
        return {};
    }
    L = l;
    U = u;
    mols = w;
    return addMolecule(0, 0, {});
}

Compilation message (stderr)

molecules.cpp: In function 'vi addMolecule(const int&, const int&, const std::unordered_set<int>&)':
molecules.cpp:21:11: warning: comparison of integer expressions of different signedness: 'const int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   21 |     if (i >= mols.size())
      |         ~~^~~~~~~~~~~~~~
molecules.cpp: In function 'vi find_subset(int, int, vi)':
molecules.cpp:62:13: warning: unused variable 'i' [-Wunused-variable]
   62 |         int i = 0;
      |             ^

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