Submission #1285630

#	Time	Username	Problem	Language	Result	Execution time	Memory
1285630		k30tonhu	Knapsack (NOI18_knapsack)	C++20	100 / 100	53 ms	11300 KiB

knapsack

#include <bits/stdc++.h>
#define ll long long
#define ii pair<ll, ll>
#define iii pair<ii, ll>
#define fi first
#define se second
using namespace std;
const int N = (1e5 + 10);
const int S = 2010;
ll n, s, cnt = 0, ans = 0;
ll power[40], dp[S];
ii b[N*40];
iii a[N];
priority_queue <ll> p[S];

signed main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
//    freopen("centroid12.inp", "r", stdin);
//    freopen("centroid12.out", "w", stdout);

    cin >> s >> n;
    for (int i = 1; i <= n; i++)
        cin >> a[i].fi.fi >> a[i].fi.se >> a[i].se;

    power[0] = 1;
    for (int i = 1; i <= 29; i++)
        power[i] = power[i - 1] * 2;

    for (int i = 1; i <= n; i++)
    {
        ll r = a[i].se, val, w;
        for (int j = 0; j <= 29; j++)
        {
            if (r < power[j])
                continue;
            r -= power[j];
            val = power[j] * a[i].fi.fi, w = power[j] * a[i].fi.se;
            if (w <= s)
                p[w].push(val);
        }
        val = r * a[i].fi.fi, w = r * a[i].fi.se;
        if (r != 0 && (w <= s))
            p[w].push(val);
    }

    for (int i = 0; i <= s; i++)
    {
        if (p[i].empty())
            continue;
        ll len = p[i].size() - s/i;
        while (!p[i].empty() && p[i].size() != len)
        {
            b[++cnt] = {i, p[i].top()};
            p[i].pop();
        }
    }

    for (int i = 1; i <= cnt; i++)
        for (int j = s; j >= b[i].fi; j--)
            dp[j] = max(dp[j], dp[j - b[i].fi] + b[i].se);

    for (int i = 0; i <= s; i++)
        ans = max(ans, dp[i]);

    cout << ans;

    return 0;
}

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