Submission #672860

#	Time	Username	Problem	Language	Result	Execution time	Memory
672860		tbzard	Arranging Shoes (IOI19_shoes)	C++14	10 / 100	89 ms	134988 KiB

shoes

#include <bits/stdc++.h>
using namespace std;
int pos[200002], t[200002];
stack<int> st[200002];
int query(int i){
    int ans = 0;
    for(;i>0;i-=(i&-i)) ans += t[i];
    return ans;
}
void update(int i){
    for(;i<=200000;i+=(i&-i)) t[i]++;
}
long long count_swaps(vector<int> s){
    int n = s.size()/2;
    for(int i=n+n;i>=1;i--){
        if(st[-s[i-1]+n].empty()) st[s[i-1]+n].push(i);
        else pos[i] = st[-s[i-1]+n].top(), st[-s[i-1]+n].pop();
    }
    long long ans = 0;
    for(int i=1;i<=n+n;i++){
        if(pos[i] == 0) continue;
        int cur_pos1 = i + query(2*n) - query(i);
        int cur_pos2 = pos[i] + query(2*n) - query(pos[i]);
        ans += cur_pos2 - cur_pos1 - 1;
        if(s[i-1] > 0) ans++;
        update(pos[i]);
    }
    return ans;
}

• Subtask 1: 10 / 10
• Subtask 2: 0 / 20
• Subtask 3: 0 / 20
• Subtask 4: 0 / 15
• Subtask 5: 0 / 20
• Subtask 6: 0 / 15