Submission #1011139

#	Time	Username	Problem	Language	Result	Execution time	Memory
1011139		rythm_of_knight	Arranging Shoes (IOI19_shoes)	C++14	10 / 100	0 ms	348 KiB

shoes

#include "shoes.h"
#include <bits/stdc++.h>
#define ll long long
using namespace std;
 
struct Fenwick{
    vector<int> tr;
    int sz;
    Fenwick(int N){
        tr.resize(N+1);
        sz=N;
    }
    void add(ll i, ll x){
        for (; i<=sz; i+=(-i&i)) tr[i]+=x;
    }
    ll get(ll i){
        ll sum=0;
        for (; i; i-=(i&-i)) sum+=tr[i];
        return sum;
    }
};
long long count_swaps(vector<int> s) {
	int n = s.size(), x;
	ll ans = 0, res = 0;
    vector <int> v = s;
    // cin >> n;
//    sgt st;
//    st.init(n);
    Fenwick tr(n+2);
	int p = 0, m = 0;
    for (int i = 0; i < n; i++) {
//        cin >> x;
        x = s[i];
        // x = v[i];
        if (x > 0) {
            if (m) {
                m--;
                int it = 0, j = i;
                for (; it < j && s[it] != -x && s[it + 1] != x; it++);
                // int l = it + tr.get(it+1), r = i;
                it++;
                // cout << it << ' ' << j << ' ';
                while (j > it)
                    swap(s[j], s[j - 1]), j--, res++;
                // ans += r - l - 1;
                // tr.add(l+1, 1);
                // tr.add(r+2, -1);
            } else {
                p++;
            }
        } else {
            x = -x;
            if (p) {
                p--;
                int j = i, it = 0;
                for (; it < j && s[it] != x && s[it + 1] != -x; it++);
                // cout << it << ' ' << j << ' ' << flush;
                while (j > it)
                    swap(s[j], s[j - 1]), j--, res++;
                // int l = it + tr.get(it+1), r = i;
                // ans += r - l;
                // tr.add(l+1, 1);
                // tr.add(r+2, -1);
            } else {
                m++;
            }
        }
    }
	return res;
}

Compilation message (stderr)

shoes.cpp: In function 'long long int count_swaps(std::vector<int>)':
shoes.cpp:24:5: warning: unused variable 'ans' [-Wunused-variable]
   24 |  ll ans = 0, res = 0;
      |     ^~~

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