Submission #880411

#	Time	Username	Problem	Language	Result	Execution time	Memory
880411		cpptowin	Knapsack (NOI18_knapsack)	C++17	100 / 100	57 ms	42696 KiB

knapsack

#include <bits/stdc++.h>
#define fo(i, d, c) for (int i = d; i <= c; i++)
#define fod(i, c, d) for (int i = c; i >= d; i--)
#define maxn 1000010
#define N 2010
#define fi first
#define se second
#define pb emplace_back
#define en cout << "\n";
#define int long long
#define inf 1000000000
#define pii pair<int, int>
#define vii vector<pii>
#define lb(x) x & -x
#define bit(i, j) ((i >> j) & 1)
#define offbit(i, j) (i ^ (1 << j))
#define onbit(i, j) (i | (1 << j))
#define vi vector<int>
template <typename T1, typename T2>
bool minimize(T1 &a, T2 b)
{
    if (a > b)
    {
        a = b;
        return true;
    }
    return false;
}
template <typename T1, typename T2>
bool maximize(T1 &a, T2 b)
{
    if (a < b)
    {
        a = b;
        return true;
    }
    return false;
}
using namespace std;
struct things
{
    int v, w, k;
} a[maxn];
int n, s;
namespace sub1
{
    void solve()
    {
        cout << min(s / a[1].w, a[1].k) * a[1].v;
    }
}
namespace sub2
{
    int dp[N];
    void solve()
    {
        fo(i, 1, n)
        {
            fod(j, s, 1) if (j >= a[i].w)
                dp[j] = max(dp[j], dp[j - a[i].w] + a[i].v);
        }
        cout << dp[s];
    }
}
namespace sub3
{
    int dp[maxn];
    vector<things> arr;
    void solve()
    {
        fo(i, 1, n)
        {
            fo(j, 1, min(s / a[i].w, a[i].k)) arr.push_back({a[i].v, a[i].w, 1});
        }
        for (auto [v, w, k] : arr)
        {
            fod(j, s, 1) if (j >= w)
                dp[j] = max(dp[j], dp[j - w] + v);
        }
        cout << dp[s];
    }
}
namespace full
{
    vii adj[N];
    int dp[N][N];
    vi v;
    void solve()
    {
        fo(i, 1, n)
        {
            if (a[i].w <= s and a[i].k > 0)
                adj[a[i].w].pb(a[i].v, a[i].k), v.pb(a[i].w);
        }
        sort(v.begin(), v.end());
        v.erase(unique(v.begin(), v.end()), v.end());
        fo(i, 0, (int)v.size()) fo(j, 0, s) dp[i][j] = -inf;
        dp[0][0] = 0;
        for (int i = 0; i < v.size(); i++)
        {
            int it = v[i];
            sort(adj[it].begin(), adj[it].end(), greater<pii>());
            // two pointer
            fo(sum, 0, s)
            {
                dp[i + 1][sum] = max(dp[i + 1][sum], dp[i][sum]);
                int profit = 0, pos = 0, used = 0, tot = 0;
                while (tot + it <= sum and pos < adj[it].size())
                {
                    tot += it;
                    used++;
                    profit += adj[it][pos].fi;
                    dp[i + 1][sum] = max(dp[i + 1][sum], dp[i][sum - tot] + profit);
                    if (used == adj[it][pos].se)
                    {
                        if (pos < adj[it].size())
                        {
                            used = 0;
                            pos++;
                        }
                        else break;
                    }
                }
            }
        }
        cout << *max_element(dp[(int)v.size()],dp[(int)v.size()] + s + 1);
    }
}
main()
{
#define name "TASK"
    if (fopen(name ".inp", "r"))
    {
        freopen(name ".inp", "r", stdin);
        freopen(name ".out", "w", stdout);
    }
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cin >> s >> n;
    fo(i, 1, n) cin >> a[i].v >> a[i].w >> a[i].k;
    if (n == 1)
        sub1::solve();
    else
        full::solve();
    // else if(n <= 100) sub3::solve();
}

Compilation message (stderr)

knapsack.cpp: In function 'void full::solve()':
knapsack.cpp:99:27: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   99 |         for (int i = 0; i < v.size(); i++)
      |                         ~~^~~~~~~~~~
knapsack.cpp:108:48: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  108 |                 while (tot + it <= sum and pos < adj[it].size())
      |                                            ~~~~^~~~~~~~~~~~~~~~
knapsack.cpp:116:33: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  116 |                         if (pos < adj[it].size())
      |                             ~~~~^~~~~~~~~~~~~~~~
knapsack.cpp: At global scope:
knapsack.cpp:129:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
  129 | main()
      | ^~~~
knapsack.cpp: In function 'int main()':
knapsack.cpp:134:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  134 |         freopen(name ".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
knapsack.cpp:135:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  135 |         freopen(name ".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~

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