Submission #144525

#	Time	Username	Problem	Language	Result	Execution time	Memory
144525		dndhk	Arranging Shoes (IOI19_shoes)	C++14	100 / 100	188 ms	18524 KiB

shoes

#include "shoes.h"
#include <bits/stdc++.h>

#define pb push_back
#define all(v) ((v).begin(), (v).end())
#define sortv(v) sort(all(v))
#define sz(v) ((int)(v).size())
#define uniqv(v) (v).erase(unique(all(v)), (v).end())
#define umax(a, b) (a)=max((a), (b))
#define umin(a, b) (a)=min((a), (b))
#define FOR(i,a,b) for(int i = (a); i <= (b); i++)
#define rep(i,n) FOR(i,1,n)
#define rep0(i,n) FOR(i,0,(int)(n)-1)
#define FI first
#define SE second
#define INF 2000000000
#define INFLL 1000000000000000000LL


using namespace std;
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;

const int MAX_N = 100000;

int N;
vector<int> vt[2][MAX_N+1];
int l[MAX_N+1], r[MAX_N+1];
bool chk[MAX_N+1];

struct SEG{
    struct NODE{
        int l, r;
        int sum;
    };
    int SZ;
    vector<NODE> seg;
    void Init(int x){
        SZ = x;
        seg.pb({-1, -1, 0});
        init(0, 0, SZ-1);
    }
    void init(int idx, int s, int e){
        if(s==e)    return;
        seg[idx].l = seg.size(); seg.pb({-1, -1, 0});
        seg[idx].r = seg.size(); seg.pb({-1, -1, 0});
        init(seg[idx].l, s, (s+e)/2); init(seg[idx].r, (s+e)/2+1, e);
    }
    void Update(int x, int y){
        update(0, 0, SZ-1, x, y);
    }
    void update(int idx, int s, int e, int x, int y){
        seg[idx].sum+=y;
        if(s==e)    return;
        if(x<=(s+e)/2)    update(seg[idx].l, s, (s+e)/2, x, y);
        else    update(seg[idx].r, (s+e)/2+1, e, x, y);
    }
    int Sum(int x, int y){
        return sum(0, 0, SZ-1, x, y);
    }
    int sum(int idx, int s, int e, int x, int y){
        if(x<=s && e<=y)    return seg[idx].sum;
        else if(x>e || y<s)    return 0;
        return sum(seg[idx].l, s, (s+e)/2, x, y) + sum(seg[idx].r, (s+e)/2+1, e, x, y);
    }
};

SEG Seg;

int zero(int x){
    return (x>0) ? x : -x;
}
long long count_swaps(std::vector<int> S) {
    N = S.size();
    Seg.Init(N);
    for(int i=0; i<N; i++){
        Seg.Update(i+1, 1);
        if(S[i]<0){
            vt[0][-S[i]].pb(i);
        }else{
            vt[1][S[i]].pb(i);
        }
    }
    int idx = 1;
    for(int i=1; i<=N/2; i++){
        while(!vt[1][i].empty()){
            r[idx] = vt[1][i].back();
            l[idx] = vt[0][i].back();
            S[vt[1][i].back()] = idx;
            S[vt[0][i].back()] = -idx;
            idx++; vt[1][i].pop_back(); vt[0][i].pop_back();
        }
    }
    ll ans = 0;
    for(int i=0; i<N; i++){
        if(chk[zero(S[i])])    continue;
        int now = zero(S[i]); chk[now] = true;
        if(S[i]<0){
            ans += (ll)Seg.Sum(i+1, r[now]-1);
            Seg.Update(r[now], -1);
        }else{
            ans += (ll)Seg.Sum(i+1, l[now]-1);
            Seg.Update(l[now], -1);
            ans++;
        }
    }
    return ans;
}

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