Submission #919440

#	Time	Username	Problem	Language	Result	Execution time	Memory
919440		imann	Knapsack (NOI18_knapsack)	C++17	73 / 100	1052 ms	48308 KiB

knapsack

#include <iostream>
#include <vector>
#include <cmath>

typedef long long ll;

const int MAX_N = 1000*100 + 10;
const int MAX_S = 2*1000 + 10;
int Vs[MAX_N];
int Ws[MAX_N];
int Ks[MAX_N];

void build_e(std::vector<int> &WWs, std::vector<int> &VVs, int num, int w, int v) {
  if (num <= 0)
    return;
  int c = std::log2(num + 1);
  int t = 1;
  for (int j = 0; j < c; j++) {
    WWs.push_back(t * w);
    VVs.push_back(t * v);
    t *= 2;
  }
  build_e(WWs, VVs, num - (t - 1), w, v);
}

std::pair<std::vector<int>, std::vector<int> > build(int n) {
  std::vector<int> WWs, VVs;
  for (int i = 0; i < n; ++i)
    build_e(WWs, VVs, Ks[i], Ws[i], Vs[i]);
  return {WWs, VVs};
}

int solve(const std::vector<int> &WWs, const std::vector<int> &VVs, int s) {
  int dp[s + 1] = {};
  for (int j = 1; j <= s; ++j) {
    if (j >= WWs[0])
      dp[j] = VVs[0];
  }
  for (int i = 1; i < WWs.size(); ++i) {
    int dp2[s + 1] = {};
    for (int j = 1; j <= s; ++j) {
      dp2[j] = std::max(dp2[j], dp[j]);
      if (WWs[i] <= j)
        dp2[j] = std::max(dp2[j], dp[j - WWs[i]] + VVs[i]);
    }
    for (int j = 1; j <= s; ++j)
      dp[j] = dp2[j];
  }
  return dp[s];
}

int main() {
  int s, n; std::cin >> s >> n;
  for (int i = 0; i < n; ++i) {
    std::cin >> Vs[i] >> Ws[i] >> Ks[i];
    Ks[i] = std::min(Ks[i], s);
  }
  auto vecs = build(n);
  std::cout << solve(vecs.first, vecs.second, s) << std::endl;
}

Compilation message (stderr)

knapsack.cpp: In function 'int solve(const std::vector<int>&, const std::vector<int>&, int)':
knapsack.cpp:39:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   39 |   for (int i = 1; i < WWs.size(); ++i) {
      |                   ~~^~~~~~~~~~~~

• Subtask 1: 12 / 12
• Subtask 2: 17 / 17
• Subtask 3: 20 / 20
• Subtask 4: 24 / 24
• Subtask 5: 0 / 27