Submission #727480

#	Time	Username	Problem	Language	Result	Execution time	Memory
727480		josiftepe	Detecting Molecules (IOI16_molecules)	C++14	0 / 100	63 ms	65536 KiB

molecules

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

struct node {
    int idx, at, weight;
    node () {}
    node(int _at, int _weight, int _idx){
        idx = _idx;
        at = _at;
        weight = _weight;
    }
    bool operator != (const node &tmp) {
        if(idx == tmp.idx and at == tmp.at and weight == tmp.weight) {
            return false;
        }
        return true;
    }
};
int dp[10005][1005];
node backtrac[10005][1005];
vector<int> v;
int rec(int at, int weight) {
    if(weight == 0) {
        backtrac[at][weight] = node(-1, -1, -1);
        return 1;
    }
    if(at == -1) {
        return 0;
    }
    if(dp[at][weight] != -1) {
        return dp[at][weight];
    }
    int r1 = 0, r2 = 0;
    if(weight - v[at] >= 0) {
        r1 = rec(at - 1, weight - v[at]);
    }
    r2 =  rec(at - 1, weight);
    
    if(r1 > r2) {
        backtrac[at][weight] = node(at - 1, weight - v[at], at);
    }
    else {
        backtrac[at][weight] = node(at - 1, weight, -1);
        
    }
    return dp[at][weight] = max(r1, r2);
}
vector<int> find_subset(int l, int u, vector<int> w) {
    v  =w;
    int n = w.size();
    int W = -1;
    memset(dp, -1, sizeof dp);
    for(int i = l; i <= u; i++) {
        if(rec(n - 1, i) == 1) {
            W = i;
            break;
        }
    }
    if(W == -1) {
        return {};
    }
    node at;
    vector<pair<int, int> > res;
    int tmp = 0;
    vector<int> R;
//    cout << backtrac[n - 1][W].at << " " << backtrac[n - 1][W].weight << endl;
    for(at = node(n - 1, W, n - 1); at.at != -1; at = backtrac[backtrac[at.at][at.weight].at][backtrac[at.at][at.weight].weight]) {
        //cout << at.at << " " << at.weight << " " << at.idx << endl;
        if(at.idx != -1) {
            R.push_back(at.idx + 1);
//            cout << at.idx + 1 << endl;
        }
    }
   
    return R;
}

Compilation message (stderr)

molecules.cpp: In function 'std::vector<int> find_subset(int, int, std::vector<int>)':
molecules.cpp:65:9: warning: unused variable 'tmp' [-Wunused-variable]
   65 |     int tmp = 0;
      |         ^~~

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