Submission #497226

#	Time	Username	Problem	Language	Result	Execution time	Memory
497226		SinsAries	Knapsack (NOI18_knapsack)	C++17	100 / 100	88 ms	4968 KiB

knapsack

#include<bits/stdc++.h>

using namespace std;

// type
using ll = long long;
using ld = long double;
using db = double;
using str = string;

// pairs
using pi = pair<int,int>;
using pl = pair<ll,ll>;
using pd = pair<db,db>;

// vector
using vi = vector<int>;
using vb = vector<bool>;
using vl = vector<ll>;
using vd = vector<db>;
using vs = vector<str>;
using vpi = vector<pi>;
using vpl = vector<pl>;
using vpd = vector<pd>;
#define pb push_back
#define pf push_front
#define all(x) x.begin(), x.end()
#define sz(x) x.size()
#define sor(x) sort(all(x))
#define rsz resize
#define rtn return

// binary search
#define lb lower_bound
#define ub upper_bound
template<class T> ll lwb(vector<T>& a, const T& b) { rtn lb(all(a), b) - a.begin(); }
template<class T> ll upb(vector<T>& a, const T& b) { rtn ub(all(a), b) - a.begin(); }

// pairs
#define mp make_pair
#define f first
#define s second

// loops
#define FOR(i,a,b) for (ll i = (a); i < (b); ++i)
#define F0R(i,a) FOR(i,0,a)
#define ROF(i,a,b) for (ll i = (b)-1; i >= (a); --i)
#define R0F(i,a) ROF(i,0,a)
#define each(a,x) for (auto& a: x)
#define cont continue
#define bre break

// FILE I/O
void setIn(str s) { freopen(s.c_str(),"r",stdin); }
void setOut(str s) { freopen(s.c_str(),"w",stdout); }
void setIO(str s) {
    setIn(s+".inp"); setOut(s+".out");
}

const int MOD = 998244353; //1e9 + 7;
const int MX = 2e5+5;
const ll INF = 1e18;
const db PI = acos((db)-1);
const int dx[4] = {1,0,-1,0}, dy[4] = {0,1,0,-1};
template<class T> using pqg = priority_queue<T,vector<T>,greater<T>>;

// modulo, exponentiation, inverse
ll pow_mod(ll a, ll b, ll m) { ll res = 1; while(b){ res = res * (b & 1 ? a : 1) % m; a = a * a % m; b >>= 1; } rtn res; }
ll inv(ll a, ll m) { rtn pow_mod(a, m - 2, m); }

ll nxt(void){ // fast way for cin operation
    ll x; cin >> x;
    rtn x;
}

#define MXN 100001

ll limit, n, val, wt, num, dp[2][2001];

map<ll, vpl> byWeight;

void init(void){
    cin >> limit >> n;
    F0R(i, n){
        cin >> val >> wt >> num;
        byWeight[wt].pb({val, num});
    }
    F0R(i, 2) F0R(j, 2001) dp[i][j] = -1;
    dp[0][0] = 0;
}

void solve(void){
    for(auto &[w, items] : byWeight){
        sort(all(items), greater<pl>());

        ll curUsed = 0;
        ll copies = 0;
        ll profit = 0;
        ll idx = 0;

        while(idx < sz(items) && (copies + 1) * w <= limit){
            copies++;
            profit += items[idx].f;
            F0R(i, limit + 1){
                dp[1][i] = max(dp[1][i], dp[0][i]);
                if(i >= copies * w && dp[0][i - copies * w] != -1)
                    dp[1][i] = max(dp[1][i], dp[0][i - w * copies] + profit);
            }

            curUsed++;
            if(curUsed == items[idx].s){
                curUsed = 0;
                idx++;
            }
        }

        swap(dp[0], dp[1]);

//        cout << w << ": \n";
//        F0R(i, limit + 1)
//            cout << dp[0][i] << ' ';
//        cout << '\n';
    }
    cout << *max_element(dp[0], dp[0] + limit + 1);
}

int main(){
    ios_base::sync_with_stdio(false); cin.tie(0);
//    setIO("CodeforcesEasy");

    init();
    solve();

    rtn 0;
}

Compilation message (stderr)

knapsack.cpp: In function 'void solve()':
knapsack.cpp:101:19: warning: comparison of integer expressions of different signedness: 'll' {aka 'long long int'} and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  101 |         while(idx < sz(items) && (copies + 1) * w <= limit){
      |                   ^
knapsack.cpp: In function 'void setIn(str)':
knapsack.cpp:54:28: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   54 | void setIn(str s) { freopen(s.c_str(),"r",stdin); }
      |                     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~
knapsack.cpp: In function 'void setOut(str)':
knapsack.cpp:55:29: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   55 | void setOut(str s) { freopen(s.c_str(),"w",stdout); }
      |                      ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~

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