Submission #826732

#	Time	Username	Problem	Language	Result	Execution time	Memory
826732		kevinsogo	Arranging Shoes (IOI19_shoes)	C++17	50 / 100	1090 ms	32536 KiB

shoes

#include <bits/stdc++.h>
using namespace std;
#include "shoes.h"
using ll = long long;

ll count_swaps(vector<int> _seq) {
    unordered_map<ll,int> found;
    vector<ll> seq, aseq;
    for (int v : _seq) seq.push_back(ll(v) * _seq.size() + ((v > 0) - (v < 0)) * found[v]++);
    unordered_map<ll,int> pos;
    for (int i = 0; i < seq.size(); i++) pos[seq[i]] = i;
    for (ll v : seq) if (v > 0) aseq.push_back(v);
    sort(aseq.begin(), aseq.end(), [&](int i, int j) {
        int d = min(pos[i], pos[-i]) - min(pos[j], pos[-j]);
        return d ? d < 0 : i < j;
    });
    vector<int> targ;
    for (int v : aseq) for (int s : {-1, +1}) targ.push_back(pos[s * v]);
    ll ans = 0;
    for (int j = 0; j < targ.size(); j++) {
        for (int i = 0; i < j; i++) if (targ[i] > targ[j]) ans++;
    }
    return ans;
}

Compilation message (stderr)

shoes.cpp: In function 'll count_swaps(std::vector<int>)':
shoes.cpp:11:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   11 |     for (int i = 0; i < seq.size(); i++) pos[seq[i]] = i;
      |                     ~~^~~~~~~~~~~~
shoes.cpp:20:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   20 |     for (int j = 0; j < targ.size(); j++) {
      |                     ~~^~~~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 20 / 20
• Subtask 3: 0 / 20
• Subtask 4: 0 / 15
• Subtask 5: 20 / 20
• Subtask 6: 0 / 15