Submission #813093

#	Time	Username	Problem	Language	Result	Execution time	Memory
813093		AliVu	Knapsack (NOI18_knapsack)	C++17	0 / 100	3 ms	596 KiB

knapsack

#include <bits/stdc++.h>
using namespace std;
#define int long long
#define el '\n'
const int maxn = 2e3 + 3, N = 1e5 + 5;
int dp[2][maxn];
vector<pair<int, int>> a;

void Solve() {
    int S, n; cin >> S >> n;
    for(int i = 1; i <= n; i++) {
        int v, w, k; cin >> v >> w >> k;
        int p = 1;
        while(p < k) {
            a.push_back({v * p, w * p});
            k -= p;
            p <<= 1;
        }
        if(k) a.push_back({v * k, w * k});
    }
    for(int i = 0; i < 2; i++) for(int j = 0; j < maxn; j++) {
        dp[i][j] = -1;
        if(j == 0) dp[i][j] = 0;
    }

    for(int k = 0; k < a.size(); k++) {
        int i = k % 2;
        for(int j = 0; j < maxn; j++) {
            if(dp[i][j] != -1 && j + a[k].second < maxn)
                dp[1 - i][j + a[k].second] = max(dp[1 - i][j + a[k].second], dp[i][j] + a[k].first);
            dp[1 - i][j] = max(dp[1 - i][j], dp[i][j]);
        }
    }

    int ans = 0;
    for(int i = 1; i <= S; i++) ans = max({ans, dp[0][i], dp[1][i]});
    cout << ans;
}
signed main() {
    ios_base::sync_with_stdio(false);cin.tie(0);
    #ifndef ONLINE_JUDGE
    freopen("inp.txt", "r", stdin);freopen("out.txt", "w", stdout);
    #endif
    int t = 1;// cin >> t;
    while(t--) Solve();
}

Compilation message (stderr)

knapsack.cpp: In function 'void Solve()':
knapsack.cpp:26:22: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   26 |     for(int k = 0; k < a.size(); k++) {
      |                    ~~^~~~~~~~~~
knapsack.cpp: In function 'int main()':
knapsack.cpp:42:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   42 |     freopen("inp.txt", "r", stdin);freopen("out.txt", "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~
knapsack.cpp:42:43: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   42 |     freopen("inp.txt", "r", stdin);freopen("out.txt", "w", stdout);
      |                                    ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~

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