Submission #836157

#	Time	Username	Problem	Language	Result	Execution time	Memory
836157		_martynas	Minerals (JOI19_minerals)	C++14	40 / 100	400 ms	26312 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(F, D)
*/
void solve(set<int> A, set<int> B) {
    assert(A.size() == B.size());
    if(A.empty()) return;
    // found a pair
    if(A.size() == 1) {
        M[*A.begin()] = *B.begin();
        return;
    }
    // check which scenario solve is in
    // 1. all A are in, no B are in
    // 2. all A are in, all B are in
    // 3. no A are in, no B are in
    int ina = 0;
    for(int a : A) {
        if(in.count(a)) ina++;
    }
    assert(ina == A.size() || ina == 0);
    int inb = 0;
    for(int b : B) {
        if(in.count(b)) inb++;
    }
    assert(inb == B.size() || inb == 0);
    // 
    int ops = 0;
    set<int> C, D, E, F;
    // split A into C and D
    int split = A.size()/2;
    auto ita = A.begin();
    for(int i = 0; i < split; i++) {
        C.insert(*ita);
        // ensure all C are in
        if(!in.count(*ita)) {
            Query(*ita); in.insert(*ita);
            ops++;
        }
        ita = next(ita);
    }
    while(ita != A.end()) {
        D.insert(*ita);
        // ensure no D are in
        if(in.count(*ita)) {
            Query(*ita); in.erase(*ita);
            ops++;
        }
        ita = next(ita);
    }
    // take and put back from C to get accurate resp value
    int resp; Query(*C.begin());
    ops++;
    resp = Query(*C.begin());
    ops++;
    // ------------------
    if(inb == 0) {
        // none of B are in
        for(int b : B) {
            int nresp = Query(b); in.insert(b);
            ops++;
            if(nresp != resp) {
                F.insert(b);
                resp = nresp;
            }
            else {
                E.insert(b);
            }
        }
        solve(C, E), solve(F, D);
    }
    else {
        // all from B are in
        for(int b : B) {
            int nresp = Query(b); in.erase(b);
            ops++;
            if(nresp != resp) {
                F.insert(b);
                resp = nresp;
            }
            else {
                E.insert(b);
            }
        }
        solve(C, E), solve(F, D);
    }
    // cout << A.size() << " " << B.size() << " " << ops << "\n";
}

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:31:16: warning: comparison of integer expressions of different signedness: 'int' and 'std::set<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   31 |     assert(ina == A.size() || ina == 0);
      |            ~~~~^~~~~~~~~~~
minerals.cpp:36:16: warning: comparison of integer expressions of different signedness: 'int' and 'std::set<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   36 |     assert(inb == B.size() || inb == 0);
      |            ~~~~^~~~~~~~~~~

• 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