Submission #252240

#	Time	Username	Problem	Language	Result	Execution time	Memory
252240		cjoa	Detecting Molecules (IOI16_molecules)	C++11	100 / 100	67 ms	7272 KiB

molecules

#include "molecules.h"

#include <vector>
#include <algorithm>
#include <utility>
#include <numeric>
#include <cassert>
#include <cstdio>

using namespace std;

typedef pair<int,int> II;

std::vector<int> find_subset(int l, int u, std::vector<int> w) {
   if (accumulate(w.begin(), w.end(), 0LL) < l)
      return {};

   const int N = w.size();

   vector<II> V;
   for (int i = 0; i < N; ++i) {
      V.push_back({w[i], i});
   }
   sort(V.begin(), V.end());

   if (V.begin()->first > u)
      return {};

   vector<long long> psum(N+1);
   for (int i = 1; i <= N; ++i)
      psum[i] = psum[i-1] + V[i-1].first;

// fprintf(stderr, "l:%d  u:%d\n", l, u);

   for (int R = 1; R <= N; ++R) {
      if (psum[R] < l) continue;
      int L = lower_bound(psum.begin(), psum.begin()+R, psum[R]-u) - psum.begin();
   // fprintf(stderr, "L:%d  R:%d  psum[R]:%lld\n", L, R, psum[R]);
      if (psum[R] - psum[L] >= l) {
         vector<int> res;
         for (int i = L+1; i <= R; ++i)
            res.push_back(V[i-1].second);
         return res;
      }
   }

   return {};
}

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