Submission #849183

#	Time	Username	Problem	Language	Result	Execution time	Memory
849183		nxson	Knapsack (NOI18_knapsack)	C++17	29 / 100	9 ms	16220 KiB

knapsack

#include<bits/stdc++.h>

using namespace std;

#define fi first
#define se second
#define pb push_back
#define sz(x) (int)(x).size()
#define sqr(x) ((x) * (x))
#define log2i(x) (64 - __builtin_clzll(1ll * (x)) - 1)
#define all(x)         x.begin(),x.end()
#define rall(x)        x.rbegin(),x.rend()
#define debug(x) { cout << #x << " = "; cout << (x) << endl; }
#define rr(x)          sort(all(x)),x.resize((unique(all(x))-x.begin()));

template<typename T> using vt = vector<T>;
using ll = long long;
using ld = long double;
using vi = vt<int>;
using ii = pair<int, int>;
using vii = vt<ii>;

const ll INF=4e18;
const int inf=INT_MAX;
const int MOD=1000000003;
const int d4i[4]={-1, 0, 1, 0}, d4j[4]={0, 1, 0, -1};
const int d8i[8]={-1, -1, 0, 1, 1, 1, 0, -1}, d8j[8]={0, 1, 1, 1, 0, -1, -1, -1};

template<class U, class V> std::ostream& operator << (std::ostream& out, const std::pair<U, V>& p) {return out << '(' << p.first << ", " << p.second << ')';}   //cout pair type
template<typename T> using minpq = priority_queue<T, vt<T>,greater<T>>;
template<typename T> using maxpq = priority_queue<T>;

ll fgcd(ll a, ll b) {while(b) swap(b, a %= b); return a;}
ll fpow(ll a, ll b, const ll c) { ll ans = 1; a %= c; for(; b; b >>= 1, a = a * a % c) if(b & 1) ans = ans * a % c; return ans;}
ll fpow(ll a, ll b) {ll ans = 1; for(; b; b >>= 1, a *= a) if(b & 1) ans *= a; return ans;}
int flog(int x) {return 31 - __builtin_clz(x);}
int flog(ll x) {return 63 - __builtin_clzll(x);}

void setIO(string name) {
    cin.tie(0)->sync_with_stdio(0);
    if(sz(name)) {
        freopen((name+".inp").c_str(), "r", stdin);
        freopen((name+".out").c_str(), "w", stdout);
    }
}

int n,s;
vt<ll> k,w,v;
ll dp[2001][2001][10] = {0};
ll f[2001][2001];

void sub3(){
    ll ans=0;
    for (int i=1;i<=n;i++){
        for (int j=0;j<=s;j++){
            dp[i][j][0]=dp[i-1][j][k[i-1]];
            dp[i][j][1] = dp[i-1][j][k[i-1]];
            if (j-w[i]>=0) dp[i][j][1]= max (dp[i][j][1],dp[i-1][j-w[i]][k[i-1]]+v[i]);
            for (int cnt=2;cnt<=k[i];cnt++){
                dp[i][j][cnt] = dp[i][j][cnt-1];
                if (j - cnt*w[i] >= 0) dp[i][j][cnt] = max(dp[i][j][cnt] , dp[i][j-w[i]][k[i-1]] + v[i]);
                ans=max(ans,dp[i][j][cnt]);
                //cout<<i<<' '<<j<<' '<<cnt<<'\n';
                //debug(dp[i][j][cnt]);
            }
            //cout<<'\n';
        }
        //cout<<'\n';
    }
    cout<<ans;
}

void sub2(){
    for (int i=1;i<=n;i++){
        for (int j=0;j<=s;j++){
            f[i][j] = f[i-1][j];
            if (j>=w[i])         f[i][j] = max(f[i][j], f[i-1][j-w[i]]+v[i]);
        }
    }
    cout<<f[n][s];
}

int main(){
    setIO("");
    cin>>s>>n;
    k.resize(n+1,0);
    w.resize(n+1,0);
    v.resize(n+1,0);
    
    for (int i=1;i<=n;i++){
        cin>>v[i]>>w[i]>>k[i];
    }
    if (n==1)   {cout<<min(k[1],s/w[1]) * v[1]; return 0; }
    if (*max_element(k.begin()+1,k.end()) == 1)   sub2();
    else if (*max_element(k.begin()+1,k.end()) <= 10)    sub3();
}

/* https://oj.uz/problem/view/NOI18_knapsack */
/*g++ -std=c++17 -O2 -Wall "knapsack.cpp" -o main.exe 
./main.exe*/

Compilation message (stderr)

knapsack.cpp: In function 'void setIO(std::string)':
knapsack.cpp:42:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   42 |         freopen((name+".inp").c_str(), "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
knapsack.cpp:43:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   43 |         freopen((name+".out").c_str(), "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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