Submission #1265636

#	Time	Username	Problem	Language	Result	Execution time	Memory
1265636		tkhoi13	Knapsack (NOI18_knapsack)	C++20	100 / 100	146 ms	124080 KiB

knapsack

#include <bits/stdc++.h>
#define ll long long
#define db double
#define pii pair<int, int>
#define fi first
#define se second
#define pb push_back
#define all(x) begin(x), end(x)
#define allr(x) rbegin(x), rend(x)
#define szx(x) ((int)(x).size())
#define FOR(i, a, b) for (int i = a, _b = (b); i <= _b; ++i)
#define ROF(i, a, b) for (int i = a, _b = (b); i >= _b; --i)
#define REP(i, n) for (int i = 0, _n = (n); i < _n; ++i)
#define endl '\n'
#define inf 1000000007
#define mod 1000000007

using namespace std;

void setIO(string filename = "") {
    ios::sync_with_stdio(0);
    cin.tie(0);
    if (!filename.empty()) {
        if (ifstream(filename + ".in")) {
            freopen((filename + ".in").c_str(), "r", stdin);
            freopen((filename + ".out").c_str(), "w", stdout);
        }
    }
}

void solve() {
    int s, n;
    cin >> s >> n;
    map<int, vector<pii>> mp;

    REP(_, n) {
        int v, w, k;
        cin >> v >> w >> k;
        mp[w].pb({v, k});
    }

    vector<pii> x;
    for (auto [wei, pi] : mp) {
        sort(all(pi), [&](pii& a, pii& b) { return a.fi > b.fi; });
        int cnt = 0, i = 0;
        while (cnt < s / wei && i < szx(pi)) {
            x.pb({pi[i].fi, wei});
            cnt++;
            pi[i].se--;
            if (!pi[i].se) i++;
        }
        // cout << "log: " << cnt << ' ' << wei << endl;
    }
    // for (auto [a, b] : x) cout << a << ' ' << b << endl;
    // cout << szx(x) + 1 << endl;

    vector<vector<int>> dp(szx(x) + 1, vector<int>(s + 1));

    // dp[0][s] = 0;
    FOR(i, 1, szx(x)) {
        FOR(j, 0, s) {
            dp[i][j] = dp[i - 1][j];
            if (j >= x[i - 1].se)
                dp[i][j] = max(dp[i][j], dp[i - 1][j - x[i - 1].se] + x[i - 1].fi);
        }
    }

    cout << dp[szx(x)][s];
}

int main() {
    // setIO("spainting");
    int t = 1;
    // cin >> t;
    while (t--) solve();
}

Compilation message (stderr)

knapsack.cpp: In function 'void setIO(std::string)':
knapsack.cpp:25:20: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   25 |             freopen((filename + ".in").c_str(), "r", stdin);
      |             ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
knapsack.cpp:26:20: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   26 |             freopen((filename + ".out").c_str(), "w", stdout);
      |             ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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