Submission #243086

#	Time	Username	Problem	Language	Result	Execution time	Memory
243086		idtj	Arranging Shoes (IOI19_shoes)	C++14	Compilation error	0 ms	0 KiB

shoes

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

signed main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    freopen("input.txt", "r", stdin);

    int n;
    cin >> n;

    vector<deque<pair<int, int>>> a(n + 1); // pos / is_left
    vector<pair<int, int>> in(n * 2); // size / is_left

    for (int i = 0; i < n * 2; ++i) {
        int now;
        cin >> now;
        if (now < 0) {
            in[i].second = 1;
            now = -now;
        }
        in[i].first = now;
    }

    int ans = 0;

    for (int i = 0; i < n * 2; ++i) {
        auto &t = a[abs(in[i].first)];
        if (t.empty() || t.front().second == in[i].second) {
            t.push_back(make_pair(i, in[i].second));
        }
        else {
            if (t.front().second) {
                ans += i - t.front().first - 1;
            }
            else
                ans += i - t.front().first;
            t.pop_front();
        }
    }

    cout << ans << endl;

    return 0;
}

Compilation message (stderr)

shoes.cpp: In function 'int main()':
shoes.cpp:9:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
     freopen("input.txt", "r", stdin);
     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
/tmp/cczFuS0E.o: In function `main':
grader.cpp:(.text.startup+0x0): multiple definition of `main'
/tmp/cctKVwhb.o:shoes.cpp:(.text.startup+0x0): first defined here
/tmp/cczFuS0E.o: In function `main':
grader.cpp:(.text.startup+0x272): undefined reference to `count_swaps(std::vector<int, std::allocator<int> >)'
collect2: error: ld returned 1 exit status