Submission #485971

#	Time	Username	Problem	Language	Result	Execution time	Memory
485971		qwerasdfzxcl	Arranging Shoes (IOI19_shoes)	C++14	100 / 100	40 ms	9584 KiB

shoes

#include "shoes.h"
#include <bits/stdc++.h>
 
using namespace std;
typedef long long ll;
vector<int> pos[100100];
pair<int, int> a[100100];
struct Seg{
    int tree[200200], sz;
    void update(int p, int x){while(p<=sz){tree[p]+=x; p+=p&-p;}}
    int query(int r){
        int ret = 0;
        while(r){
            ret += tree[r];
            r ^= r&-r;
        }
        return ret;
    }
}tree;
 
inline int myabs(int x){
    if (x<0) return -x;
    return x;
}
 
long long count_swaps(std::vector<int> s) {
  	int n = s.size()/2;
    for (int i=n*2-1;i>=0;i--) if (s[i]<0) pos[-s[i]].push_back(i);
    ll ret = 0;
    vector<int> v1(s.size());
    int cnt = 1;
    for (int i=0;i<n*2;i++) if (s[i]>0){
        if (i<pos[s[i]].back()) ret++;
        else ret--;
        ret += myabs(i-pos[s[i]].back());
        a[cnt] = {i, pos[s[i]].back()};
        if (a[cnt].first>a[cnt].second) swap(a[cnt].first, a[cnt].second);
        v1[a[cnt].second] = a[cnt].first+1;
 
        pos[s[i]].pop_back();
        cnt++;
    }
 
    tree.sz=n*2;
    for (int i=0;i<n*2;i++){
        if (v1[i]){
            tree.update(v1[i], -1);
            ret += tree.query(v1[i])*2;
        }
        else tree.update(i+1, 1);
    }
    return ret/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