This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
#include <bits/stdc++.h>
#define file "main"
#define maxn (int) 3e6 + 5
#define ll long long
#define pii pair<ll, int>
#define fi(i, a, b) for(int i = a; i <= b; i ++)
#define fid(i, a, b) for(int i = a; i >= b; i --)
#define int long long
using namespace std;
int S, n, N;
pii a[maxn];
ll dp[2005];
 main() {
//    freopen(file".inp", "r", stdin);
    ios::sync_with_stdio(false);
    cin.tie(0);
    cin >> S >> n;
    fi(i, 1, n) {
        int v, w, k; cin >> v >> w >> k;
        for(int tmp = 1; tmp <= k; tmp *= 2) {
            ll nw_v = v * tmp, nw_w = w * tmp;
            if(nw_w <= S) a[++N] = { nw_v, nw_w };
            k -= tmp;
        }
        if(k) {
            ll nw_v = v * k, nw_w = w * k;
            if(nw_w <= S) a[++N] = { nw_v, nw_w };
        }
    }
    memset(dp, -0x3f, sizeof dp);
    dp[0] = 0;
    fi(i, 1, N) {
        fid(j, S, a[i].second) {
            dp[j] = max(dp[j], dp[j - a[i].second] + a[i].first);
        }
    }
    cout << *max_element(dp + 0, dp + S + 1);
    return 0;
}
Compilation message (stderr)
knapsack.cpp:16:2: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   16 |  main() {
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