Submission #971802

#	Time	Username	Problem	Language	Result	Execution time	Memory
971802		andro	Arranging Shoes (IOI19_shoes)	C++14	10 / 100	1 ms	348 KiB

shoes

#include <bits/stdc++.h>

#include "shoes.h"

using namespace std;

long long count_swaps(std::vector<int> s) {
	int n = s.size();
	map<int,int> M, M1;
	vector<int> a = s;
	for(int i = 0 ; i < n; i++) {
        if(a[i] > 0) {
            M[a[i]] += 1;
        }
        else {
            M1[a[i]] += 1;
        }
	}
	int ok = 0;
	for(int i = 0; i < n; i++) {
        if(a[i] > 0) {
            if(M[a[i]] != M1[-a[i]]) {
                ok = 1;
            }
        }
	}
	if(ok) {
        return - 1;
	}/*
	vector<int> izracunao(n, 0);
	int ans = 0;
	for(int i = 0; i < n; i+= 2) {
        if(a[i] > 0 && a[i] == - a[i - 1]);
        if(a[i] > 0) {
            int idx = - 1;
            for(int j = i + 1; j <= n; j++) {
                if(a[i] == - a[j]) {
                    idx = j;
                    break;
                }
            }
            //cout << 1 << " " << i << " " << idx << "\n";
            while(idx > i) {
                swap(a[idx], a[idx - 1]);
                ans += 1;
                idx -= 1;
            }
        }
        else {
            int idx = - 1;
            for(int j = i + 1; j <= n; j++) {
                if(a[i] == - a[j]) {
                    idx = j;
                    break;
                }
            }
            //cout << 2 << " " << i << " " << idx << "\n";
            while(idx > i + 1) {
                swap(a[idx], a[idx - 1]);
                ans += 1;
                idx -= 1;
            }
        }
	}
	return ans;*/
	map<int,set<int>> ms;
	for(int i = 0; i < n; i++) {
        ms[a[i]].insert(i);
	}
	vector<int> izracunao(n, 0);
	int ans = 0;
	for(int i = 0; i < n; i++) {
        if(izracunao[i]) {
            continue;
        }
        auto it = ms[-a[i]].upper_bound(i);
        if(it == ms[-a[i]].end()) {
            // znaci resio sam sve tu
            continue;
        }
        int idx = (*it);
        ms[-a[i]].erase(it);
        if(a[i] > 0) {
            //cout << 1 << " " << i << " " << idx << "\n";
            izracunao[idx] = 1;
            ans += idx - i;
        }
        else {
            //cout << 2 << " " << i << " " << idx << "\n";
            izracunao[idx] = 1;
            ans += idx - i - 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