Submission #508877

#	Time	Username	Problem	Language	Result	Execution time	Memory
508877		hqb	Knapsack (NOI18_knapsack)	C++14	49 / 100	5 ms	348 KiB

knapsack

#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define ull unsigned long long
#define ar array

const int maxN = 2e3 + 1, INF = 1e9, MOD = 1e9 + 7;
ll M,N,dp[maxN];
vector<ll> v,w;

void setIO(string name=""){
    freopen((name+".in").c_str(),"r",stdin);
    freopen((name+".out").c_str(),"w",stdout);
}
int main(){
    cin.tie(0);
    cin.sync_with_stdio(0);
    //setIO();

    cin >> M >> N;
    for (int i=0;i<N;i++){
        ll a,b,c; cin >> a >> b >> c;
        for (ll p=1;c-p>=0;c-=p,p*=2){
            v.push_back(p*a),w.push_back(p*b);
        }
        if (c>0) v.push_back(c*a),w.push_back(c*b);
    }
    for (int i=0;i<v.size();i++){
        for (int j=M;j>=w[i];j--){
            dp[j] = max(dp[j],dp[j-w[i]]+v[i])%MOD;
        }
    }
    cout << dp[M] << '\n';
    return 0;
}

Compilation message (stderr)

knapsack.cpp: In function 'int main()':
knapsack.cpp:28:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   28 |     for (int i=0;i<v.size();i++){
      |                  ~^~~~~~~~~
knapsack.cpp: In function 'void setIO(std::string)':
knapsack.cpp:12:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   12 |     freopen((name+".in").c_str(),"r",stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
knapsack.cpp:13:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   13 |     freopen((name+".out").c_str(),"w",stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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