Submission #583765

#	Time	Username	Problem	Language	Result	Execution time	Memory
583765		jack715	Knapsack (NOI18_knapsack)	C++14	73 / 100	1083 ms	7064 KiB

knapsack

#include <bits/stdc++.h>
#define ll long long
#define pb push_back
#define pp pop_back
#define mp make_pair
#define bb back
#define ff first
#define ss second
#define int long long

using namespace std;

signed main(){
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    // freopen("tmp.in", "r", stdin);
    // freopen("tmp.out", "w", stdout);

    int s, n;
    cin >> s >> n;
    vector<vector<int> > nums(n, vector<int>(3));
    for (int i = 0; i < n; i++) {       
        for (int j = 0; j < 3; j++)
            cin >> nums[i][j];
    }
    int dp[2005];
    memset(dp, -1, sizeof(dp));
    dp[0] = 0;
    for (int i = 0; i < n; i++) {
        for(int j = s; j >= 0; j --) {
            for(int x = 1; x <= nums[i][2]; x ++) {
                if(j - x * nums[i][1] < 0) break;
                if(dp[j - x * nums[i][1]] == -1) continue;
                if(dp[j] == -1) dp[j] =dp[j - x * nums[i][1]] + nums[i][0] * x;
                else dp[j] = max(dp[j], dp[j - x * nums[i][1]] + nums[i][0] * x );
            }
        }
    }
    int ans = 0;
    for(int i = 0; i <= s; i ++) {
        ans = max(ans, dp[i]);
    }
    cout << ans << '\n';
    return 0; 
}

/* stuff you should look for
    * int overflow, array bounds
    * special cases (n=1?)
    * do smth instead of nothing and stay organized
    * WRITE STUFF DOWN
    * DON'T GET STUCK ON ONE APPROACH
*/

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