Submission #571040

#	Time	Username	Problem	Language	Result	Execution time	Memory
571040		web	Detecting Molecules (IOI16_molecules)	C++17	0 / 100	1 ms	212 KiB

molecules

#include <iostream>
#include "molecules.h"
#include <algorithm>
using namespace std;

vector<vector<pair<int, int>>> dp; 
void knapsack(vector<int>& weights, int u)
{
    for(int i = 0; i<weights.size(); ++i)
    {
        for(int  weight = 0; weight <= u; ++weight)
        {
            if(weight < weights[i])
            {
                dp[i+1][weight] = dp[i][weight];
            }
            else
            {
                if(dp[i][weight].first >= dp[i][weight - weights[i]].first+ weights[i])
                {
                    dp[i+1][weight] = dp[i][weight];
                }
                else
                {
                    dp[i+1][weight] = {dp[i][weight-weights[i]].first + weights[i], i};
                }
            }
        }
    }
    
}


std::vector<int> find_subset(int l, int u, std::vector<int> w) {
    dp = vector<vector<pair<int,int>>>(w.size()+1, vector<pair<int,int>>(u+1, {0, -1})); 
    
    knapsack(w, u);
    //cout<<"begin pair: ";
    pair<int,int> currP = dp[w.size()][u];
    //cout<<currP.first<<" "<<currP.second<<endl;
    if(currP.first < l)
        return vector<int>(0);
    
    vector<int> retVal;
    int currWeight = currP.first;
    while(currP.second != -1)
    {
     
        retVal.push_back(currP.second+1);
        currP = dp[currP.second][currWeight-w[currP.second]];
        currWeight-=w[currP.second];
//        cout<<"new pair: " <<currP.first<<" "<<currP.second<<endl; 
    }

    return retVal;
}

Compilation message (stderr)

molecules.cpp: In function 'void knapsack(std::vector<int>&, int)':
molecules.cpp:9:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
    9 |     for(int i = 0; i<weights.size(); ++i)
      |                    ~^~~~~~~~~~~~~~~

• Subtask 1: 0 / 9
• Subtask 2: 0 / 10
• Subtask 3: 0 / 12
• Subtask 4: 0 / 15
• Subtask 5: 0 / 23
• Subtask 6: 0 / 31