| # | Time | Username | Problem | Language | Result | Execution time | Memory |
|---|---|---|---|---|---|---|---|
| 1293112 | trandaihao5555 | Arranging Shoes (IOI19_shoes) | C++20 | 0 ms | 0 KiB |
#include <bits/stdc++.h>
#include "shoes.h"
// #define int long long
#define debug cout << "ok\n";
#define SQR(x) (1LL * ((x) * (x)))
#define MASK(i) (1LL << (i))
#define BIT(x, i) (((x) >> (i)) & 1)
#define fi first
#define se second
#define pb push_back
#define mp make_pair
#define pii pair<int,int>
#define pli pair<ll,int>
#define vi vector<int>
#define FAST ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
typedef unsigned int ui;
//using namespace std;
const int M = 1e9 + 7;
const int INF = 1e9 + 7;
const ll INFLL = (ll)2e18 + 7LL;
const ld PI = acos(-1);
const int dx[] = {1, -1, 0, 0, -1, 1, 1, -1};
const int dy[] = {0, 0, 1, -1, -1, -1, 1, 1};
template<class _, class __>
bool minimize(_ &x, const __ y){
if(x > y){
x = y;
return true;
} else return false;
}
template<class _, class __>
bool maximize(_ &x, const __ y){
if(x < y){
x = y;
return true;
} else return false;
}
template<class _,class __>
void Add(_ &x, const __ y) {
x += y;
if (x >= M) {
x -= M;
}
return;
}
template<class _,class __>
void Diff(_ &x, const __ y) {
x -= y;
if (x < 0) {
x += M;
}
return;
}
//--------------------------------------------------------------
const int MaxN = 1e6+7;
vi nen;
multiset<int> lis[MaxN][2];
bool ch[MaxN];
struct FenwickTree {
int Tr[MaxN];
void Upd(int u,int v) {
u++;
for (; u < MaxN; u += u&-u) {
Tr[u]+=v;
}
return;
}
int Get(int u) {
u++;
if (u < 0) return 0;
int res = 0;
for (; u; u -= u&-u) {
res += Tr[u];
}
return res;
}
} Fw;
int count_swaps(vi S) {
for (int x : S) nen.pb(abs(x));
sort(nen.begin(),nen.end());
nen.erase(unique(nen.begin(),nen.end()),nen.end());
for (int i=0;i<S.size();i++) {
int & x = S[i];
int tmp = x / abs(x);
if (tmp == -1) tmp = 0;
x = lower_bound(nen.begin(),nen.end(),abs(x)) - nen.begin() + 1;
lis[x][tmp].insert(i);
}
vi res;
for (int i=0;i<S.size();i++) {
if (ch[i]) continue;
res.pb(*lis[S[i]][0].begin());
res.pb(*lis[S[i]][1].begin());
ch[*lis[S[i]][0].begin()] = true;
ch[*lis[S[i]][1].begin()] = true;
lis[S[i]][0].erase(lis[S[i]][0].begin());
lis[S[i]][1].erase(lis[S[i]][1].begin());
}
reverse(res.begin(),res.end());
ll ans = 0;
for (int x : res) {
ans += Fw.Get(x);
Fw.Upd(x,1);
}
return ans;
}
//void sol() {
// cout << count_swaps({2, 1, -1, -2});
//}
//
//signed main() {
//// freopen("test.inp","r",stdin);
//// freopen("test.out","w",stdout);
// FAST
// int t=1;
//// cin >> t;
// while (t--) sol();
//}