Submission #474382

#	Time	Username	Problem	Language	Result	Execution time	Memory
474382		aris12345678	Arranging Shoes (IOI19_shoes)	C++14	100 / 100	604 ms	148192 KiB

shoes

#include "shoes.h"
#include <bits/stdc++.h>
using namespace std;

const int mxN = 2*100005;
int bit[mxN];
bool vis[mxN];

void upd(int pos, int n) {
    while(pos <= n) {
        bit[pos]++;
        pos += (pos&(-pos));
    }
}

int ask(int pos) {
    int ans = 0;
    while(pos > 0) {
        ans += bit[pos];
        pos -= (pos&(-pos));
    }
    return ans;
}

long long count_swaps(vector<int> s) {
    int n = s.size();
    long long ans = 0;
    map<int, deque<int> > mp;
    for(int i = 0; i < n; i++)
        mp[s[i]].push_back(i+1);
    for(int i = 0; i < n; i++) {
        if(vis[i]) continue;
        mp[s[i]].pop_front();
        int neg, pos;
        if(s[i] > 0) {
            pos = i+1;
            neg = mp[-s[i]].front();
            mp[-s[i]].pop_front();
        } else {
            neg = i+1;
            pos = mp[-s[i]].front();
            mp[-s[i]].pop_front();
        }
        if(neg > pos) {
            ans += ((neg-pos)-(ask(neg)-ask(pos-1)));
            upd(neg, n);
        } else {
            ans += ((pos-neg-1)-(ask(pos)-ask(neg-1)));
            upd(pos, n);
        }
        vis[neg-1] = vis[pos-1] = true;
    }
    return ans;
}

// int main() {
//     int n;
//     scanf("%d", &n);
//     vector<int> s(n);
//     for(int i = 0; i < n; i++)
//         scanf("%d", &s[i]);
//     printf("%lld\n", count_swaps(s));
//     return 0;
// }

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