Submission #698887

#	Time	Username	Problem	Language	Result	Execution time	Memory
698887		Caubethieunang	Knapsack (NOI18_knapsack)	C++14	100 / 100	59 ms	4960 KiB

knapsack

/// (*^_^*) Author : Cau_be_thieu_nang

#include <bits/stdc++.h>
#define ll long long
#define LOG 20
#define MASK(i) (1LL<<(i))
#define BIT(x,i) (((x)>>(i))&1)
#define FIRST_BIT(mask) __builtin_ctz((mask)&(-mask))
#define ERASE_BIT(mask) (mask)^((mask)&(-mask))
#define left _left
#define right _right
#define task "t"
using namespace std;
const ll INF=1e18;
const int iat=1e6+9;
const int mod=1e9+7;
void fast_IO()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    if(fopen(task".inp","r"))
    {
        freopen(task".inp","r",stdin);
        freopen(task".out","w",stdout);
    }
}
int s,n;
vector <pair<ll,ll>> store[2001];
ll dp[2001];
signed main()
{
    fast_IO();
    cin>>s>>n;
    for(int i=1; i<=n; i++)
    {
        int v,w,k;
        cin>>v>>w>>k;
        store[w].push_back({v,k});
    }
    for(int weight=0; weight<=s; weight++)
    {
        if(store[weight].empty())continue;
        sort(store[weight].begin(),store[weight].end(),greater<pair<ll,ll>>());
        int pos=0;
        for(int i=0; weight*i<s; i++)
        {
            if(pos>=store[weight].size())break;
            for(int lim=s; lim>=weight; lim--)dp[lim]=max(dp[lim],dp[lim-weight]+store[weight][pos].first);
            store[weight][pos].second--;
            if(!store[weight][pos].second)pos++;
        }
    }
    cout<<dp[s];
}

Compilation message (stderr)

knapsack.cpp: In function 'int main()':
knapsack.cpp:49:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   49 |             if(pos>=store[weight].size())break;
      |                ~~~^~~~~~~~~~~~~~~~~~~~~~
knapsack.cpp: In function 'void fast_IO()':
knapsack.cpp:25:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   25 |         freopen(task".inp","r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
knapsack.cpp:26:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   26 |         freopen(task".out","w",stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~

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