Submission #448342

#	Time	Username	Problem	Language	Result	Execution time	Memory
448342		mnair797	Knapsack (NOI18_knapsack)	C++14	100 / 100	75 ms	7252 KiB

knapsack

#include <bits/stdc++.h>
#define sz(x) int(x.size())
#define all(x) x.begin(),x.end()
#define reset(x) memset(x, 0,sizeof(x))
#define pb push_back
#define mp make_pair
#define fi first
#define se second
#define N 100005
#define remain(x) if (x > MOD) x -= MOD
#define ii pair<int, int>
#define iiii pair< ii , ii >
#define viiii vector< iiii >
#define vi vector<int>
#define vii vector< ii >
#define bit(x, i) (((x) >> (i)) & 1)
#define Task "test"
#define int long long
 
using namespace std;
 
typedef long double ld;
const int inf = 1e10;
const int minf = -1e10;
 
int s, n;
int v[N], w[N], k[N];
 
void readfile()
{
    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);
    }
    cin >> s >> n;
    for(int i=1; i<=n; i++) cin >> v[i] >> w[i] >> k[i];
}
 
void proc()
{
    vector<int> dp(s+1,0);
    vector<ii> obj[s+1];
    for(int i=1; i<=n; i++) obj[w[i]].pb(ii(v[i],k[i]));
    for(int i=0; i<=s; i++){
        if (obj[i].size()==0) continue;
        sort(obj[i].begin(),obj[i].end(),greater<ii>());
        int id = 0;
        for(int j=0; j*i < s; j++){
            if (id >= obj[i].size()) break;
            for(int k=s; k>=i; k--){
                dp[k] = max(dp[k], dp[k-i] + obj[i][id].fi);
            }
            obj[i][id].se--;
            if (obj[i][id].se==0) id++;
        }
    }
    cout << dp[s];
}
 
signed main()
{
    readfile();
    proc();
    return 0;
}

Compilation message (stderr)

knapsack.cpp: In function 'void proc()':
knapsack.cpp:52:20: 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]
   52 |             if (id >= obj[i].size()) break;
      |                 ~~~^~~~~~~~~~~~~~~~
knapsack.cpp: In function 'void readfile()':
knapsack.cpp:35:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   35 |         freopen(Task".inp","r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~

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