Submission #1096057

#	Time	Username	Problem	Language	Result	Execution time	Memory
1096057		InvMOD	Knapsack (NOI18_knapsack)	C++14	73 / 100	2 ms	604 KiB

knapsack

#include <bits/stdc++.h>
using namespace std;

#define fi first
#define se second
#define gcd __gcd
#define siz(v) v.size()
#define pb push_back
#define pi pair<int,int>
#define all(v) (v).begin(), (v).end()
#define compact(v) (v).erase(unique(all(v)), (v).end())
#define FOR(i, a, b) for(int i = (a); i <= (b); i++)
///#define int long long

using ll = long long;
using ld = long double;
using ull = unsigned long long;

template<typename T> bool ckmx(T& a, const T& b){if(a < b) return a = b, true; return false;}
template<typename T> bool ckmn(T& a, const T& b){if(a > b) return a = b, true; return false;}

const int N = 2e3+1;



int S, n, k[N], id[N];
ll dp[N], v[N], w[N], answer;

void process(ll cur_w, ll cur_val){
    if(cur_w > S) return;
    for(int i = S; i >= cur_w; i--){
        ckmx(dp[i], dp[i-cur_w] + cur_val);
        ckmx(answer, dp[i]);
    }
    return;
}

void solve()
{
    cin >> S >> n;
    for(int i = 1; i <= n; i++){
        cin >> v[i] >> w[i] >> k[i];
        id[i] = i;
    }

    sort(id+1, id+1+n, [&](int x, int y){
            return v[x] > v[y];
    });

    for(int i = 1; i <= min(n,S); i++){
        ll cur_k = min(S, k[id[i]]);
        ll cur_v = v[id[i]], cur_w = w[id[i]];
        for(int j = 0; j < (32 - __builtin_clz(cur_k)); j++){
            if(cur_k >= (1<<j)){
                cur_k -= (1<<j);
                process(cur_w * (1<<j), cur_v * (1<<j));
            }
            else break;
        }
        if(cur_k){
            process(cur_w * cur_k, cur_v * cur_k);
        }
    }

    cout << answer <<"\n";
}

signed main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);

    #define name "InvMOD"
    if(fopen(name".INP", "r")){
        freopen(name".INP","r",stdin);
        freopen(name".OUT","w",stdout);
    }

    int t = 1; //cin >> t;
    while(t--) solve();
    return 0;
}

Compilation message (stderr)

knapsack.cpp: In function 'int main()':
knapsack.cpp:76:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   76 |         freopen(name".INP","r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
knapsack.cpp:77:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   77 |         freopen(name".OUT","w",stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 12 / 12
• Subtask 2: 17 / 17
• Subtask 3: 20 / 20
• Subtask 4: 24 / 24
• Subtask 5: 0 / 27