Submission #433077

#	Time	Username	Problem	Language	Result	Execution time	Memory
433077		Pichon5	Arranging Shoes (IOI19_shoes)	C++17	100 / 100	606 ms	31684 KiB

shoes

#include "shoes.h"
#include <bits/stdc++.h>
#define pb push_back
#define vi vector<int>
#define F first
#define S second
#define ll long long
using namespace std;
const int tam=200005;
ll T[tam];
int n;
void update(int pos, int val){
    while(pos<=n){
        T[pos]+=val;
        pos+=(pos&-pos);
    }
}
ll query(int pos){
    ll res=0;
    while(pos>0){
        res+=T[pos];
        pos-=(pos&-pos);
    }
    return res;
}
long long count_swaps(vi s) {
    n=s.size();
    map<int,set<int> >M;
    for(int i=1;i<=n;i++){
        update(i,1);
        M[s[i-1]].insert(i);
    }
    ll ans=0;
    for(int i=0;i<n;i++){
        auto it=M[s[i]].find(i+1);
        if(it==M[s[i]].end())continue;
        auto A=M[-s[i]].begin();
        int b=i+1,e=*A;
        ll Q=query(e-1)-query(b);
        ans+=Q;
        if(s[i]>0)ans++;
        update(e,-1);
        M[-s[i]].erase(A);
        auto I = M[s[i]].begin();
        M[s[i]].erase(I);
    }
    return ans;
}
//2

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