Submission #1220286

#	Time	Username	Problem	Language	Result	Execution time	Memory
1220286		khoile08	Knapsack (NOI18_knapsack)	C++20	37 / 100	1 ms	328 KiB

knapsack

#include <bits/stdc++.h>
using namespace std;
#define FOR(i,a,b) for(int i = a; i <= b; i++)
#define FOD(i,a,b) for(int i = a; i >= b; i--)
//#define int long long
#define fi first
#define se second
#define pb push_back
#define ll long long
#define ull unsigned long long
#define db double
#define lcm(a,b) a / __gcd(a, b) * b
#define ii pair<int,int>
#define iii pair<int,pair<int,int>>
#define iv pair<pair<int,int>,pair<int,int>>
#define sq(a) (a) * (a)
#define MASK(i) (1LL << i)
#define task "task"

const int inf = 1e9;
const ll INF = 1e18;
const int mod = 1e9 + 7;
const int N = 1e5 + 5;
const int S = 2005;

int n, s;
int v[N], w[N], a[N];
ll dp[S];

void Solve() {
    FOR(i, 1, n) {
        ll pw = 1;
        while(a[i] >= pw && pw * w[i] <= s) {
            FOD(j, s, pw * w[i]) dp[j] = max(dp[j], dp[j - pw * w[i]] + 1LL * v[i] * pw);
            a[i] -= pw;
            pw <<= 1;
        }
        if(a[i] > 0 && a[i] * w[i] <= s) FOD(j, s, a[i] * w[i]) dp[j] = max(dp[j], dp[j - a[i] * w[i]] + 1LL * a[i] * v[i]);
    }
    ll ans = 0;
    FOR(i, 0, s) ans = max(ans, dp[i]);
    cout << ans << '\n';
}

signed main() {
    if(fopen(task".inp", "r")) {
        freopen(task".inp", "r", stdin);
        freopen(task".out", "w", stdout);
    }
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);

    int test = 1;
//    cin >> test;
    while(test--) {
        cin >> s >> n;
        FOR(i, 1, n) cin >> v[i] >> w[i] >> a[i];
        Solve();
    }
}

Compilation message (stderr)

knapsack.cpp: In function 'int main()':
knapsack.cpp:47:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   47 |         freopen(task".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
knapsack.cpp:48:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   48 |         freopen(task".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

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