Submission #836088

#	Time	Username	Problem	Language	Result	Execution time	Memory
836088		_martynas	Minerals (JOI19_minerals)	C++14	40 / 100	142 ms	21360 KiB

minerals

#include "minerals.h"
#include <bits/stdc++.h>

using namespace std;

set<int> in;
map<int, int> M;

/*
solve(A, B)
A -> C D
B -> E F
solve(C, E), solve(D, F)
*/
void solve(set<int> A, set<int> B) {
    assert(A.size() == B.size());
    if(A.empty()) return;
    if(A.size() == 1) {
        M[*A.begin()] = *B.begin();
        return;
    }
    if(!in.empty()) {
        // todo: optimize to not take out needed minerals
        for(int x : in) Query(x);
        in.clear();
    }
    auto ita = A.begin();
    set<int> C, D, E, F;
    int resp;
    int split = A.size()/2;
    for(int i = 0; i < split; i++) {
        C.insert(*ita); in.insert(*ita);
        resp = Query(*ita);
        ita = next(ita);
    }
    assert(resp == C.size());
    while(ita != A.end()) D.insert(*ita), ita = next(ita);
    for(int b : B) {
        int nresp = Query(b); in.insert(b);
        if(nresp != resp) {
            F.insert(b);
            resp = nresp;
        }
        else {
            E.insert(b);
        }
    }
    solve(C, E), solve(D, F);
}

void Solve(int N) {
    // sub2: all 1, 2, ..., N are in the first half and in the second half
    set<int> A, B;
    int resp = -1, nresp;
    for(int i = 1; i <= 2*N; i++) {
        nresp = Query(i);
        in.insert(i);
        if(resp != nresp) {
            A.insert(i);
            resp = nresp;
        }
        else {
            B.insert(i);
        }
    }
    solve(A, B);
    // for(auto p : M) {
    //     cout << p.first << " " << p.second << "\n";
    // }
    for(auto p : M) {
        Answer(p.first, p.second);
    }
}

Compilation message (stderr)

In file included from /usr/include/c++/10/cassert:44,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:33,
                 from minerals.cpp:2:
minerals.cpp: In function 'void solve(std::set<int>, std::set<int>)':
minerals.cpp:36:17: warning: comparison of integer expressions of different signedness: 'int' and 'std::set<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   36 |     assert(resp == C.size());
      |            ~~~~~^~~~~~~~~~~
minerals.cpp:36:12: warning: 'resp' may be used uninitialized in this function [-Wmaybe-uninitialized]
   36 |     assert(resp == C.size());
      |            ^~~~

• Subtask 1: 6 / 6
• Subtask 2: 25 / 25
• Subtask 3: 9 / 9
• Subtask 4: 0 / 30
• Subtask 5: 0 / 5
• Subtask 6: 0 / 5
• Subtask 7: 0 / 5
• Subtask 8: 0 / 5
• Subtask 9: 0 / 10