Submission #1118286

#	Time	Username	Problem	Language	Result	Execution time	Memory
1118286		crafticat	Detecting Molecules (IOI16_molecules)	C++17	9 / 100	1 ms	604 KiB

molecules

#include <bits/stdc++.h>
#include "molecules.h"

using namespace std;

template<typename T>
using V = vector<T>;
using ll = long long;
using vi = V<int>;
using pi = pair<int,int>;
constexpr int INF = 1e9 + 7;

#define F0R(i, n) for (int i = 0; i < n;i++)
#define FOR(i, j , n) for (int i = j ;i < n;i++)

vi possible(ll l, ll u, vi w, int k) {
    int ptrEnd = w.size() - k; //including
    int ptrStart = 0; // Not including

    ll curSum = 0;
    FOR(i, ptrEnd, w.size())
        curSum += w[i];

    while (curSum > u && ptrStart < k) {
        curSum -= w[ptrEnd]; ptrEnd++;
        curSum += w[ptrStart]; ptrStart++;
    }

    if (curSum <= u && curSum >= l) {
        vi vals;
        F0R(i, ptrStart)
            vals.push_back(i);
        FOR(i, ptrEnd, w.size()) {
            vals.push_back(i);
        }
        return vals;
    }
    return {};
}

std::vector<int> find_subset(int l, int u, std::vector<int> w) {
    sort(w.begin(), w.end());
    ll offset = w[0];

    for (auto &x : w)
        x -= offset;

    V<ll> prefixSums(w.size() + 1), revPrefixSums(w.size() + 1); // Not including, including
    F0R(i, w.size()) {
        prefixSums[i + 1] = prefixSums[i] + w[i];
    }
    F0R(i, w.size()) {
        prefixSums[i] = prefixSums[i + 1] + w[i];
    }

    FOR(k, 1, w.size() + 1) {
        if ((prefixSums[k + 1] >= ll(l - k * offset)) && revPrefixSums[k] <= ll(u - k * offset)) {
            auto r = possible(l - k * offset, u - k * offset, w, k);
            if (!r.empty()) return r;
        }
    }
    return {};
}

#if DEBUG

int main() {
    int n, l, u;
    assert(3 == scanf("%d %d %d", &n, &l, &u));
    std::vector<int> w(n);
    for (int i = 0; i < n; i++)
        assert(1 == scanf("%d", &w[i]));
    std::vector<int> result = find_subset(l, u, w);

    printf("%d\n", (int)result.size());
    for (int i = 0; i < (int)result.size(); i++)
        printf("%d%c", result[i], " \n"[i == (int)result.size() - 1]);
}
#endif

Compilation message (stderr)

molecules.cpp: In function 'vi possible(ll, ll, vi, int)':
molecules.cpp:14:41: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   14 | #define FOR(i, j , n) for (int i = j ;i < n;i++)
......
   21 |     FOR(i, ptrEnd, w.size())
      |         ~~~~~~~~~~~~~~~~~~~              
molecules.cpp:21:5: note: in expansion of macro 'FOR'
   21 |     FOR(i, ptrEnd, w.size())
      |     ^~~
molecules.cpp:14:41: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   14 | #define FOR(i, j , n) for (int i = j ;i < n;i++)
......
   33 |         FOR(i, ptrEnd, w.size()) {
      |             ~~~~~~~~~~~~~~~~~~~          
molecules.cpp:33:9: note: in expansion of macro 'FOR'
   33 |         FOR(i, ptrEnd, w.size()) {
      |         ^~~
molecules.cpp: In function 'std::vector<int> find_subset(int, int, std::vector<int>)':
molecules.cpp:13:37: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   13 | #define F0R(i, n) for (int i = 0; i < n;i++)
......
   49 |     F0R(i, w.size()) {
      |         ~~~~~~~~~~~                  
molecules.cpp:49:5: note: in expansion of macro 'F0R'
   49 |     F0R(i, w.size()) {
      |     ^~~
molecules.cpp:13:37: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   13 | #define F0R(i, n) for (int i = 0; i < n;i++)
......
   52 |     F0R(i, w.size()) {
      |         ~~~~~~~~~~~                  
molecules.cpp:52:5: note: in expansion of macro 'F0R'
   52 |     F0R(i, w.size()) {
      |     ^~~
molecules.cpp:14:41: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   14 | #define FOR(i, j , n) for (int i = j ;i < n;i++)
......
   56 |     FOR(k, 1, w.size() + 1) {
      |         ~~~~~~~~~~~~~~~~~~               
molecules.cpp:56:5: note: in expansion of macro 'FOR'
   56 |     FOR(k, 1, w.size() + 1) {
      |     ^~~

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