Submission #971807

#	Time	Username	Problem	Language	Result	Execution time	Memory
971807		andro	Arranging Shoes (IOI19_shoes)	C++14	10 / 100	1 ms	544 KiB

shoes

#include <bits/stdc++.h>

#include "shoes.h"

using namespace std;

const int N = 1e5 + 5;

struct fenw {
    int t[N] = {0};
    int query(int i) {
        int ans = 0;
        for(; i > 0; i -= i & - i) {
            ans += t[i];
        }
        return ans;
    }
    void update(int i, int v) {
        for(; i < N; i += i & - i) {
            t[i] += v;
        }
    }
}fenw;

long long count_swaps(std::vector<int> s) {
	int n = s.size();
	vector<int> a(n + 1);
	for(int i = 1; i <= n; i++) {
        a[i] = s[i - 1];
	}
	map<int,int> M, M1;
	for(int i = 1; i <= n; i++) {
        if(a[i] > 0) {
            M[a[i]] += 1;
        }
        else {
            M1[a[i]] += 1;
        }
	}
	for(int i = 1; i <= n; i++) {
        if(a[i] > 0) {
            if(M[a[i]] != M1[-a[i]]) {
                return - 1;
            }
        }
	}
	map<int,set<int>> ms;
	for(int i = 1; i <= n; i++) {
        ms[a[i]].insert(i);
	}
	vector<int> izracunao(n + 1, 0);
	int ans = 0;
	for(int i = 1; i <= n; i++) {
        if(izracunao[i]) {
            continue;
        }
        auto it = ms[-a[i]].upper_bound(i);
        if(it == ms[-a[i]].end()) {
            continue;
        }
        int idx = *it;
        if(a[i] > 0) {
            //cout << 1 << " " << i << " " << idx << "\n";
            ans += (idx + fenw.query(idx)) - (i + fenw.query(i));
            fenw.update(i, 1);
            fenw.update(idx, - 1);

        }
        else {
            //cout << 2 << " " << i << " " << idx << "\n";
            ans += (idx + fenw.query(idx)) - (i + fenw.query(i)) - 1;
            fenw.update(i, 1);
            fenw.update(idx, - 1);

        }
        izracunao[idx] = 1;
	}
	return ans;
}

/*
int main() {
    cout << count_swaps({- 2, 2, 2, - 2, - 2, 2});
}*/

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