Submission #491220

#	Time	Username	Problem	Language	Result	Execution time	Memory
491220		ariloc	Knapsack (NOI18_knapsack)	C++14	100 / 100	179 ms	3648 KiB

knapsack

#include <bits/stdc++.h>
    
//#pragma GCC optimize("Ofast,unroll-loops")
//#pragma GCC target("avx,avx2,fma")
    
#define forn(i,n) for(int i = 0; i < int(n); i++)
#define forsn(i,s,n) for(int i = int(s); i < int(n); i++)
#define dforn(i,n) for (int i = int(n)-1; i >= 0; i--)
#define dforsn(i,s,n) for(int i = int(n)-1; i >= int(s); i--)
#define dbg(x) cerr << #x << " = " << x << endl;
#define all(c) (c).begin(),(c).end()
#define pb push_back
#define fst first
#define snd second
#define FAST_IO ios::sync_with_stdio(false);cin.tie(nullptr);
    
using namespace std;
typedef vector<int> vi;
typedef long long ll;
typedef long double ld;
typedef pair<int,int> ii;

const int MAXN = 1e5+5;
const int MAXW = 2005;
const ll INF = 9e18;

struct state {
    ll bst;
    int cnt_last,last;
};

struct item {
    int v,w,k;

    bool operator< (const item &o) const {
        return (double)v/w > (double)o.v/o.w;
    }
};

item types[MAXN];
state dp[MAXW];

int main() {
    int S,N; scanf("%d %d",&S,&N);

    forn(i,N) scanf("%d %d %d",&types[i].v,&types[i].w,&types[i].k);
    sort(types,types+N);

    forn(i,S+1) dp[i] = {-INF,0,-1};
    dp[0] = {0,0,-1};

    forn(i,N) {
        ll v = types[i].v;
        int w = types[i].w, k = types[i].k;
        forsn(j,w,S+1) {
            ll val = dp[j-w].bst + v;
            if (val > dp[j].bst && (dp[j-w].last != i || dp[j-w].cnt_last < k))
                dp[j] = {val, (dp[j-w].last != i ? 1 : dp[j-w].cnt_last + 1), i};
        }
    }

    forsn(i,1,S+1) dp[i].bst = max(dp[i].bst, dp[i-1].bst);

    printf("%lld",dp[S].bst);
    
    return 0;
}

Compilation message (stderr)

knapsack.cpp: In function 'int main()':
knapsack.cpp:44:19: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   44 |     int S,N; scanf("%d %d",&S,&N);
      |              ~~~~~^~~~~~~~~~~~~~~
knapsack.cpp:46:20: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   46 |     forn(i,N) scanf("%d %d %d",&types[i].v,&types[i].w,&types[i].k);
      |               ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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