Submission #572287

#	Time	Username	Problem	Language	Result	Execution time	Memory
572287		BhavayGoyal	Knapsack (NOI18_knapsack)	C++14	100 / 100	548 ms	19760 KiB

knapsack

#include <bits/stdc++.h>
using namespace std;

#define f first
#define s second

const int inf = 1e9;

int s, n;
int dp[2001][2001];
vector<vector<pair<int, int>>> arr(2001);

long long sol(int idx, int weight) {
    // base case
    if (weight < 0) return -inf;
    if (idx == s+1) return 0;
    if (dp[idx][weight] != -1) return dp[idx][weight];
    long long ans = 0;
    // not include
    ans = max(ans, sol(idx+1, weight));
    // include
    int currVal = 0, currwt = 0;
    for (int i = 0; i < arr[idx].size(); i++) {
        int count = arr[idx][i].s;
        bool f = true;
        while (count > 0) {
            currVal += arr[idx][i].f;
            currwt += idx;
            if (currwt > weight) {
                break;
                f = false;
            }
            count--;
            ans = max(ans, currVal + sol(idx+1, weight - currwt));
        }
        if (!f) break;
    }
    return dp[idx][weight] = ans;
}

int main () {
    cin >> s >> n;
    for (int i = 0; i < n; i++) {
        int v, w, k; cin >> v >> w >> k;
        if (w > s || k <= 0) continue;
        arr[w].push_back({v, k});
    } 
    for (int i = 0; i <= 2000; i++) sort (arr[i].begin(), arr[i].end(), greater<>());
    memset(dp, -1, sizeof dp);
    int ans = sol(1, s);
    cout << ans << endl;
}

Compilation message (stderr)

knapsack.cpp: In function 'long long int sol(int, int)':
knapsack.cpp:23:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   23 |     for (int i = 0; i < arr[idx].size(); i++) {
      |                     ~~^~~~~~~~~~~~~~~~~

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