# | Time | Username | Problem | Language | Result | Execution time | Memory |
---|---|---|---|---|---|---|---|
469575 | spike1236 | Arranging Shoes (IOI19_shoes) | C++14 | 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>
using namespace std;
#define pb push_back
#define mp make_pair
#define f first
#define s second
#define ll long long
#define ld long double
#define all(_v) _v.begin(), _v.end()
#define sz(_v) (int)_v.size()
#define pii pair <int, int>
#define pll pair <ll, ll>
#define veci vector <int>
#define vecll vector <ll>
const int dx[4] = {1, -1, 0, 0};
const int dy[4] = {0, 0, -1, 1};
const double PI = 3.1415926535897932384626433832795;
const double eps = 1e-9;
const int MOD1 = 1e9 + 7;
const int MOD2 = 998244353;
const int MAXN = 4e5 + 10;
int t[MAXN], n;
int pos[MAXN][2];
void upd(int r, int val) {
for(; r < MAXN; r += r & -r) t[r] += val;
}
int get(int r) {
int res = 0;
for(; r > 0; r -= r & -r) res += t[r];
return res;
}
ll count_swaps(veci b) {
n = sz(b) / 2;
b.insert(b.begin(), 0);
for(int i = 1; i <= 2 * n; ++i) {
upd(i, 1);
int x = b[i];
if(x < 0) pos[-x][0] = i;
else pos[x][1] = i;
}
ll ans = 0;
vector <pii> seg;
for(int i = 1; i <= n; ++i) {
int l = pos[i][0], r = pos[i][1];
if(l > r) ++ans, swap(l, r);
seg.pb(mp(l, r));
}
sort(all(seg));
for(auto p : seg) {
int l = p.f, r = p.s;
ans += get(r - 1) - get(l);
upd(l, -1);
upd(r, -1);
}
return ans;
}
void solve() {
}
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
int CNT_TESTS = 1;
///cin >> CNT_TESTS;
for(int NUMCASE = 1; NUMCASE <= CNT_TESTS; ++NUMCASE) {
solve();
if(NUMCASE != CNT_TESTS) cout << '\n';
}
return 0;
}