| # | Time | Username | Problem | Language | Result | Execution time | Memory |
|---|---|---|---|---|---|---|---|
| 582230 | xynex | Arranging Shoes (IOI19_shoes) | C++17 | 0 ms | 0 KiB |
This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
#include <bits/stdc++.h>
//#include "shoes.h"
using namespace std;
#define ll long long
#define dl double long
#define ull unsigned long long
#define pr pair
#define vt vector
#define ff first
#define ss second
#define mp make_pair
#define sz(a) (int)a.size()
#define pb push_back
#define pf push_front
#define popB pop_back
#define popF pop_front
#define bit_count __builtin_popcount
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define sp(x) fixed << setprecision(x)
template<typename T> T get_rand(T l, T r) {
random_device rd;
mt19937 gen(rd());
return uniform_int_distribution<T>(l, r)(gen);
}
template<typename T> T lcm(T a, T b) { return a * (b / __gcd(a, b)); }
template<class A> void read(vt<A>& v);
template<class A, size_t S> void read(array<A, S>& a);
template<class T> void read(T& x) { cin >> x; }
void read(double& d) { string t; read(t); d = stod(t); }
void read(long double& d) { string t; read(t); d = stold(t); }
template<class H, class... T> void read(H& h, T&... t) { read(h); read(t...); }
template<class A> void read(vt<A>& x) { for (auto& a : x) read(a); }
template<class A, size_t S> void read(array<A, S>& x) { for (auto& a : x) read(a); }
string to_string(char c) { return string(1, c); }
string to_string(bool b) { return b ? "true" : "false"; }
string to_string(const char* s) { return string(s); }
string to_string(string s) { return s; }
string to_string(vt<bool> v) { string res; for (int i = 0; i < sz(v); ++i) res += char('0' + v[i]); return res; }
template<size_t S> string to_string(bitset<S> b) { string res; for (int i = 0; i < S; ++i) res += char('0' + b[i]); return res; }
template<class T> string to_string(T v) { bool f = 1; string res; for (auto x : v) { if (!f) res += ' '; f = 0; res += to_string(x); } return res; }
template<class A> void write(A x) { cout << to_string(x); }
template<class H, class... T> void write(const H& h, const T&... t) { write(h); write(t...); }
void print() { write("\n"); }
template<class H, class... T> void print(const H& h, const T&... t) { write(h); if (sizeof...(t)) write(' '); print(t...); }
void freop(string s) {
freopen((s + ".in").c_str(), "r", stdin);
freopen((s + ".out").c_str(), "w", stdout);
}
const int MOD = 1e9 + 7;
const int N = 3e6 + 5;
const ll INF = 9e18;
const int M = 3e3 + 5;
const dl pi = acos(-1);
const dl eps = 1e-12;
const int sq = 700;
int dx[] = {-1, 0, 1, 0};
int dy[] = {0, -1, 0, 1};
/* ll vs int*/
int n;
ll sum[N], z[N];
void push(int tl, int tr, int v) {
if(tl != tr) {
z[v * 2] += z[v];
z[v * 2 + 1] += z[v];
}
sum[v] += z[v] * 1ll * (tr - tl + 1);
z[v] = 0;
}
void upd(int l, int r, int tl = 0, int tr = n - 1, int v = 1) {
push(tl, tr, v);
if(tl > r || tr < l) return;
if(tl >= l && tr <= r) {
z[v]++;
push(tl, tr, v);
return;
}
int mid = (tl + tr) >> 1;
upd(l, r, tl, mid, v * 2); upd(l, r, mid + 1, tr, v * 2 + 1);
}
int get(int l, int r, int tl = 0, int tr = n - 1, int v = 1) {
push(tl, tr, v);
if(tl > r || tr < l) return 0;
if(tl >= l && tr <= r) return sum[v];
int mid = (tl + tr) >> 1;
return get(l, r, tl, mid, v * 2) + get(l, r, mid + 1, tr, v * 2 + 1);
}
ll count_swaps(vt<int> s) {
n = sz(s);
for(int i = 1; i <= 4 * n; ++i) z[i] = 0, sum[i] = 0;
vt<int> right[n + 1];
vt<int> left[n + 1];
vt<bool> used(n);
for(int i = 0; i < n; ++i) {
if(s[i] < 0) left[-s[i]].pb(i);
else right[s[i]].pb(i);
}
ll ans = 0;
int whr = n - 1;
for(int i = n - 1; i >= 0; --i) {
if(used[i]) continue;
int L = left[abs(s[i])].back();
left[abs(s[i])].pop_back();
int R = right[abs(s[i])].back();
right[abs(s[i])].pop_back();
ans += abs((R - get(R, R)) - whr);
//ans += get(R, whr);
// print(R - get(R, R), whr, ans);
upd(R, n - 1);
whr--;
ans += abs((L - get(L, L)) - whr);
//ans += get(L, whr);
// print(L - get(L, L), whr, ans);
upd(L, n - 1);
whr--;
used[L] = 1, used[R] = 1;
}
return ans;
}
int main() {
int n;
assert(1 == scanf("%d", &n));
vector<int> S(2 * n);
for (int i = 0; i < 2 * n; i++)
assert(1 == scanf("%d", &S[i]));
fclose(stdin);
long long result = count_swaps(S);
printf("%lld\n", result);
fclose(stdout);
return 0;
}