Submission #735308

#	Time	Username	Problem	Language	Result	Execution time	Memory
735308		That_Salamander	Detecting Molecules (IOI16_molecules)	C++17	100 / 100	45 ms	5580 KiB

molecules

#include <iostream>
#include <algorithm>
#include <string>
#include <vector>
#include <cmath>
#include <map>
#include <set>
#include <cstring>
#include <queue>
#include <unordered_set>
#include <unordered_map>
#include <cassert>
#include <random>

#define FOR(var,bound) for(int var = 0; var < bound; var++)
#define FORB(var,lb,ub) for (int var = lb; var < ub; var++)
#define FORR(var,bound) for(int var = bound-1; var >= 0; var--)
#define int long long

//#define RANDOMISE

using namespace std;

typedef long long ll;
typedef vector<int> vi;
typedef vector<vector<int>> vvi;
typedef pair<int, int> pii;

vector<signed> find_subset(signed l, signed u, vector<signed> w) {
    vector<int> sortedPerm(w.size());
    FOR(i, w.size()) sortedPerm[i] = i;
    sort(sortedPerm.begin(), sortedPerm.end(), [&](int a, int b) {
        return w[a] < w[b];
    });

    int sum = 0;

    int li = 0;
    int ri = -1;

    while (ri < (int) w.size() && li < w.size()) {
        if (l <= sum && sum <= u) {
            vector<signed> res;

            for (int i = li ; i <= ri; i++) {
                res.push_back(sortedPerm[i]);
            }

            return res;
        } else if (sum < l) {
            if (ri + 1 < (int) w.size()) {
                sum += w[sortedPerm[++ri]];
            } else break;
        } else {
            sum -= w[sortedPerm[li++]];
        }
    }

    return {};
}

#ifdef LOCAL_TEST
signed main() {
#ifdef RANDOMISE
    FOR(iter, 10000) {
#endif

    signed n, l, u;

#ifdef RANDOMISE
    n = 100;
    l = rand() % 1000 + 1;
    if (l == 1000) {
        u = 1000;
    } else {
        u = l + (rand() % (1001 - l));
    }

    vector<signed> w(n);
    fill(w.begin(), w.end(), rand() % 100 + 1);
#else
    assert(3 == scanf("%d %d %d", &n, &l, &u));
    std::vector<signed> w(n);
    for (int i = 0; i < n; i++)
        assert(1 == scanf("%d", &w[i]));
#endif
    std::vector<signed> result = find_subset(l, u, w);
    
#ifdef RANDOMISE
    if (result.size()  == 0) {
        int count = (l + w[0] - 1) / w[0];
        int mres = w[0] * count;

        if (mres >= l && mres <= u && count <= n) {
            cout << "Didn't find solution!" << endl;
            cout << "w = " << w[0] << " range = [" << l << ", " << u << "]" << endl;
            exit(0);
        }
    } else {
        int res = 0;
        for (int i: result) {
            res += w[i];
        }

        if (res < l) {
            cout << "Too small!" << endl;
            exit(0);
        }

        if (res > u) {
            cout << "Too big!" << endl;
            exit(0);
        }

        set<int> unique(result.begin(), result.end());
        if (unique.size() != result.size()) {
            cout << "Duplicate molecules!" << endl;
            cout << "w = " << w[0] << " range = [" << l << ", " << u << "]" << endl;
            exit(0);
        }
    }
    }
#else
    printf("%d\n", (signed) result.size());
    for (int i = 0; i < (int)result.size(); i++)
        printf("%d%c", result[i], " \n"[i == (signed)result.size() - 1]);
#endif
}
#endif

Compilation message (stderr)

molecules.cpp: In function 'std::vector<int> find_subset(int, int, std::vector<int>)':
molecules.cpp:15:45: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   15 | #define FOR(var,bound) for(int var = 0; var < bound; var++)
......
   31 |     FOR(i, w.size()) sortedPerm[i] = i;
      |         ~~~~~~~~~~~                          
molecules.cpp:31:5: note: in expansion of macro 'FOR'
   31 |     FOR(i, w.size()) sortedPerm[i] = i;
      |     ^~~
molecules.cpp:41:38: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   41 |     while (ri < (int) w.size() && li < w.size()) {
      |                                   ~~~^~~~~~~~~~

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