Submission #884189

#	Time	Username	Problem	Language	Result	Execution time	Memory
884189		fanwen	Knapsack (NOI18_knapsack)	C++17	100 / 100	44 ms	3084 KiB

knapsack

#include <bits/stdc++.h>

using namespace std;

#define fi first
#define se second
#define ll long long
#define file(name)                  \
    if(fopen(name".inp", "r"))      \
        freopen(name".inp", "r", stdin), freopen(name".out", "w", stdout);

const int MAX = 2e3 + 5;

int n, S;
vector <pair <int, int>> weights[MAX];
int dp[MAX];

void you_make_it(void) {
    cin >> S >> n;
    memset(dp, -0x3f, sizeof dp);
    dp[0] = 0;
    for (int i = 1; i <= n; ++i) {
        int v, w, k; cin >> v >> w >> k;
        weights[w].emplace_back(v, k);
    }
    for (int i = 1; i <= S; ++i) {
        if(weights[i].empty()) continue;
        sort(weights[i].begin(), weights[i].end(), greater <pair <int, int>>());
        int ind = 0;
        for (int j = 0; j < S / i; ++j) {
            if(ind >= weights[i].size()) break;
            for (int s = S; s >= i; --s) {
                dp[s] = max(dp[s], dp[s - i] + weights[i][ind].fi);
            }
            weights[i][ind].se--;
            if(weights[i][ind].se == 0) ind++;
        }
    }
    cout << *max_element(dp, dp + S + 1);
}

signed main() {

#ifdef LOCAL
    freopen("TASK.inp", "r", stdin);
    freopen("TASK.out", "w", stdout);
#endif
    file("knapsack");
    auto start_time = chrono::steady_clock::now();

    cin.tie(0), cout.tie(0) -> sync_with_stdio(0);

    you_make_it();

    auto end_time = chrono::steady_clock::now();

    cerr << "\nExecution time : " << chrono::duration_cast <chrono::milliseconds> (end_time - start_time).count() << "[ms]" << endl;

    return (0 ^ 0);
}

// Dream it. Wish it. Do it.

Compilation message (stderr)

knapsack.cpp: In function 'void you_make_it()':
knapsack.cpp:31:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   31 |             if(ind >= weights[i].size()) break;
      |                ~~~~^~~~~~~~~~~~~~~~~~~~
knapsack.cpp: In function 'int main()':
knapsack.cpp:10:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   10 |         freopen(name".inp", "r", stdin), freopen(name".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
knapsack.cpp:48:5: note: in expansion of macro 'file'
   48 |     file("knapsack");
      |     ^~~~
knapsack.cpp:10:49: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   10 |         freopen(name".inp", "r", stdin), freopen(name".out", "w", stdout);
      |                                          ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
knapsack.cpp:48:5: note: in expansion of macro 'file'
   48 |     file("knapsack");
      |     ^~~~

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