Submission #411800

#	Time	Username	Problem	Language	Result	Execution time	Memory
411800		timmyfeng	Arranging Shoes (IOI19_shoes)	C++17	Compilation error	0 ms	0 KiB

shoes

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

#include <bits/extc++.h>

template <class T, class Comp = less<T>>
using ordered_set = __gnu_pbds::tree<
    T, __gnu_pbds::null_type, Comp,
    __gnu_pbds::rb_tree_tag,
    __gnu_pbds::tree_order_statistics_node_update
>;

long long count_swaps(vector<int> s) {
    int n = s.size() / 2;

    map<int, vector<int>> nxt;
    ordered_set<int> shoes;

    for (int i = 2 * n - 1; i >= 0; --i) {
        nxt[s[i]].push_back(i);
        shoes.insert(i);
    }

    long long ans = 0;
    while (!shoes.empty()) {
        auto i = *shoes.begin();
        shoes.erase(shoes.begin());

        int x = s[i];
        nxt[x].pop_back();

        int j = nxt[-x].back();
        nxt[-x].pop_back();

        ans += shoes.order_of_key(j) + (x > 0);
        shoes.erase(j);
    }

    return ans;
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);

    int n;
    cin >> n;

    vector<int> s(2 * n);
    for (int i = 0; i < 2 * n; ++i) {
        cin >> s[i];
    }

    cout << count_swaps(s) << "\n";
}

Compilation message (stderr)

/usr/bin/ld: /tmp/cc5msUwz.o: in function `main':
grader.cpp:(.text.startup+0x0): multiple definition of `main'; /tmp/ccHuxsmA.o:shoes.cpp:(.text.startup+0x0): first defined here
collect2: error: ld returned 1 exit status