Submission #388619

#	Time	Username	Problem	Language	Result	Execution time	Memory
388619		cpp219	Arranging Shoes (IOI19_shoes)	C++14	100 / 100	371 ms	410552 KiB

shoes

#pragma GCC optimization "Ofast"
#pragma GCC optimization "unroll-loop"
#pragma GCC target ("avx2")
//#include "shoes.h"
#include <bits/stdc++.h>
#define ll long long
#define ld long double
#define fs first
#define sc second
using namespace std;
const ll N = 3e5 + 6;
const ll lim = 3e5 + 6;
const ll inf = 1e9 + 7;
typedef pair<ll,ll> LL;

deque<ll> pos[N],neg[N];
ll bit[N];
bool was[N];
void upd(ll p,ll val){
    for (ll i = p;i < N;i += i & -i) bit[i] += val;
}

ll Get(ll p){
    ll res = 0;
    for (ll i = p;i > 0;i -= i & -i) res += bit[i];
    return res;
}

ll Query(ll L,ll R){
    return Get(R) - Get(L - 1);
}

ll Find(ll cond,ll id,ll x){
    if (!cond) return *lower_bound(pos[id].begin(),pos[id].end(),x);
    return *lower_bound(neg[id].begin(),neg[id].end(),x);
}

ll count_swaps(vector<int> v){
    ll n = v.size(),ans = 0;
    for (ll i = 0;i < n;i++){
        ll now = v[i];
        if (now > 0) pos[now].push_back(i);
        else neg[-now].push_back(i);
    }
    for (ll i = 0;i < n;i++){
        if (was[i]) continue;
        ll now = v[i],nxt;
        if (now < 0){
            nxt = Find(0,-now,i); ans += nxt - i - Query(i,nxt) - 1;
            pos[-now].pop_front(); neg[-now].pop_front();
        }
        else{
            nxt = Find(1,now,i); ans += nxt - i - Query(i,nxt);
            neg[now].pop_front(); pos[now].pop_front();
        }
        was[nxt] = 1; upd(nxt,1);
    }
    //exit(0);
    return ans;
}
/*
vector<int> v;
ll n,x;

int main(){
    //ios_base::sync_with_stdio(0);
    //cin.tie(0), cout.tie(0);
    #define task "test"
    if (fopen(task".inp", "r")){
        freopen(task".inp", "r", stdin);
        //freopen(task".out", "w", stdout);
    }
    cin>>n;
    for (ll i = 1;i <= 2*n;i++) cin>>x,v.push_back(x);
    cout<<count_swaps(v);
}
*/

Compilation message (stderr)

shoes.cpp:1: warning: ignoring #pragma GCC optimization [-Wunknown-pragmas]
    1 | #pragma GCC optimization "Ofast"
      | 
shoes.cpp:2: warning: ignoring #pragma GCC optimization [-Wunknown-pragmas]
    2 | #pragma GCC optimization "unroll-loop"
      |

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