Submission #440863

#	Time	Username	Problem	Language	Result	Execution time	Memory
440863		stat0r1c	Knapsack (NOI18_knapsack)	C++11	100 / 100	866 ms	3596 KiB

knapsack

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
using namespace std;
using namespace __gnu_pbds;
using ll = long long;
using ull = unsigned ll;
template<typename T> using vt = vector<T>;
using vi = vt<int>;
using vvi = vt<vi>;
using ii = pair<int, int>;
using vii = vt<ii>;
using indexed_set = tree<int,null_type,less<int>,rb_tree_tag,tree_order_statistics_node_update>;
struct chash {
    static ull hash_f(ull x) {x += 0x9e3779b97f4a7c15; x = (x ^ (x >> 30)) * 0xbf58476d1ce4e5b9; x = (x ^ (x >> 27)) * 0x94d049bb133111eb; return x ^ (x >> 31);}
    size_t operator()(ull x) const {static const ull RANDOM = chrono::steady_clock::now().time_since_epoch().count();return hash_f(x + RANDOM);}
};
struct iihash {
    template <class T1, class T2>
    size_t operator () (const pair<T1,T2> &p) const {auto h1 = hash<T1>{}(p.first);auto h2 = hash<T2>{}(p.second);return h1 ^ h2;}
};
template<class T1, class T2, class T3> using ii_umap = gp_hash_table<pair<T1,T2>,T3,iihash>;
template<class T1, class T2> using f_umap = gp_hash_table<T1,T2,chash>;
template<class T1, class T2> using o_umap = gp_hash_table<T1,T2>;
#define sqr(x) (x)*(x)
#define all(x) begin(x), end(x)
#define rall(x) (x).rbegin(), (x).rend()
#define sz(x) (int)(x).size()
#define debug(x) cerr << #x << " -> " << x << '\n'
#define F first
#define S second
#define mp make_pair
#define pb push_back
#define eb emplace_back
const int inf = 1e9 + 7;
const ll infll = 1e18 + 10;
template <typename T> inline T fgcd(T a, T b) {while(b) swap(b, a %= b); return a;}
ll fpow(ll a, ll b) {ll o = 1; for(;b;b >>= 1) {if(b & 1) o = o * a;a = a * a;} return o;}
ll fpow(ll a, ll b, ll m) {ll o = 1; a %= m; for(;b;b >>= 1) {if(b & 1) o = o * a % m;a = a * a % m;} return o;}
template<class T> void uniq(vt<T> &a) {sort(all(a));a.resize(unique(all(a)) - a.begin());}
void setIO(string name = "", string inp = "inp", string out = "out") {
    cin.tie(0)->sync_with_stdio(0);
    if(sz(name)) {
        if(sz(inp)) freopen((name+"."+inp).c_str(), "r", stdin);
        if(sz(out)) freopen((name+"."+out).c_str(), "w", stdout);
    }
}
int s,n;
struct item {
    int v,w,k;
    bool operator<(const item &p) const {
        if(v != p.v) return v > p.v;
        return w < p.w;
    }
} a[100000];
int ans[2001],anss;
int main() {
    setIO();
    cin >> s >> n;
    vi re(s + 1);
    for(int i = 1; i <= s; i++) re[i] = s / i;
    for(int i = 0; i < n; i++) {
        cin >> a[i].v >> a[i].w >> a[i].k;
    }
    sort(a, a + n);
    for(int i = 0; i < n; i++) {
        if(!re[a[i].w]) continue;
        vi l,r;
        for(int j = s - a[i].w; j > 0; j--)
            if(ans[j]) l.pb(j);
        l.pb(0);
        int cnt = 0;
        for(int j = 0; j < min(a[i].k, re[a[i].w]); j++) {
            bool ck = 0;
            for(int q : l) {
                if(ans[q] + a[i].v > ans[q + a[i].w]) {
                    ck = 1;
                    ans[q + a[i].w] = ans[q] + a[i].v;
                    if(q + a[i].w + a[i].w <= s) r.pb(q + a[i].w);
                }
            }
            if(!ck) break;
            cnt++;
            l = r;
            r.clear();
        }
        re[a[i].w] -= cnt;
    }
    for(int i = 1; i <= s; i++) anss = max(anss, ans[i]);
    cout << anss;
    return 0;
}

Compilation message (stderr)

knapsack.cpp: In function 'void setIO(std::string, std::string, std::string)':
knapsack.cpp:43:28: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   43 |         if(sz(inp)) freopen((name+"."+inp).c_str(), "r", stdin);
      |                     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
knapsack.cpp:44:28: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   44 |         if(sz(out)) freopen((name+"."+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