Submission #420917

#	Time	Username	Problem	Language	Result	Execution time	Memory
420917		yuto1115	Arranging Shoes (IOI19_shoes)	C++17	30 / 100	1090 ms	16668 KiB

shoes

#include "shoes.h"
#include <bits/stdc++.h>
#define rep(i, n) for(ll i = 0; i < ll(n); i++)
#define rep2(i, s, n) for(ll i = ll(s); i < ll(n); i++)
#define rrep(i, n) for(ll i = ll(n)-1; i >= 0; i--)
#define all(a) a.begin(),a.end()
#define rall(a) a.rbegin(),a.rend()
#define pb push_back
#define eb emplace_back
using namespace std;
using ll = long long;
using P = pair<int, int>;
using vi = vector<int>;
using vvi = vector<vi>;
using vl = vector<ll>;
using vvl = vector<vl>;
using vp = vector<P>;
using vvp = vector<vp>;
using vb = vector<bool>;
using vvb = vector<vb>;
using vs = vector<string>;

template<class T>
bool chmin(T &a, T b) {
    if (a > b) {
        a = b;
        return true;
    }
    return false;
}

template<class T>
bool chmax(T &a, T b) {
    if (a < b) {
        a = b;
        return true;
    }
    return false;
}

const int inf = 1001001001;
const ll linf = 1001001001001001001;

ll count_swaps(vi s) {
    int n = s.size() / 2;
    vvi l(n), r(n);
    rep(i, 2 * n) {
        if (s[i] < 0) l[-s[i] - 1].pb(i);
        else r[s[i] - 1].pb(i);
    }
    vp v;
    rep(i, n) rep(j, l[i].size()) v.eb(l[i][j], r[i][j]);
    assert(v.size() == n);
    vi ord(n);
    iota(all(ord), 0);
    ll ans = inf;
    auto calc_inv = [&](const vi &ls) {
        int res = 0;
        rep(i, 2 * n) rep2(j, i + 1, 2 * n) {
                res += ls[i] > ls[j];
            }
        return res;
    };
    do {
        vi now;
        rep(i, n) {
            now.pb(v[ord[i]].first);
            now.pb(v[ord[i]].second);
        }
        chmin<ll>(ans, calc_inv(now));
    } while (next_permutation(all(ord)));
    return ans;
}

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 shoes.cpp:2:
shoes.cpp: In function 'll count_swaps(vi)':
shoes.cpp:53:21: warning: comparison of integer expressions of different signedness: 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   53 |     assert(v.size() == n);
      |            ~~~~~~~~~^~~~

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