Submission #1101208

#	Time	Username	Problem	Language	Result	Execution time	Memory
1101208		Plot_Twist	Knapsack (NOI18_knapsack)	C++17	100 / 100	119 ms	35144 KiB

knapsack

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

#define int long long

bool comp(pair<int,int>&p1,pair<int,int>&p2) {
    if(p1.first==p2.first) return p1.second > p2.second;
    else return p1.first > p2.first;
} 

signed main () {
    int n,limit;
    cin>>limit>>n;

    // ------Grouping by weight----------
    map<int,vector<pair<int,int>>>mp;
    for(int i = 0; i < n; i++) {
        int val, wt, am;
        cin>>val>>wt>>am;
        if(wt<=limit && am>0)mp[wt].push_back({val,am});
    }
    // ----------------------------------


    // ------Initializing DP ------------
    int wtcnt = mp.size();
    int dp[wtcnt+1][limit+1];
    for(int i = 0; i<= wtcnt; i++) 
        for(int j = 0; j<=limit;j++) dp[i][j] = INT32_MIN;
    // ----------------------------------

    int level = 1;  
    dp[0][0] = 0;
    for(auto &[wt,arr] : mp) {
        sort(arr.begin(),arr.end(),comp);
        int sz= arr.size();
        for(int i = 0; i<=limit; i++) {
            dp[level][i] = dp[level-1][i];   // NOT TAKE
            int idx = 0;
            int value = 0;
            int amount_taken = 0;
            int curr_item_used = 0;
            while((amount_taken+1)*wt <= i && idx < sz) {
                amount_taken++;
                value+= arr[idx].first;
                if(dp[level-1][i-amount_taken*wt]!= INT32_MIN) {
                    dp[level][i] = max(dp[level][i], value + dp[level-1][i-amount_taken*wt]);
                }
                curr_item_used++;
                if(curr_item_used==arr[idx].second) {
                    idx++;
                    curr_item_used=0;
                }
            }
        }
        level++;
    }
    int ans = -1;
    for(int i = 0; i<= limit; i++) ans = max(ans, dp[wtcnt][i]);
    cout<<ans<<endl;
}

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