Submission #1286390

#	Time	Username	Problem	Language	Result	Execution time	Memory
1286390		harryleee	Arranging Shoes (IOI19_shoes)	C++20	Compilation error	0 ms	0 KiB

shoes

#include<bits/stdc++.h>
using namespace std;
const int maxn = 1e5;

vector<int> operator + (vector<int>& a, vector<int>& b){
    vector<int> res;
    int i = 0, j = 0, n = a.size(), m = b.size();
    while(i < n && j < m){
        while(i < n && a[i] <= b[j])
            res.push_back(a[i++]);
        if (i == n) break;
        while(j < m && b[j] <= a[i])
            res.push_back(b[j++]);      
    }
    while(i < n)
        res.push_back(a[i++]);
    while(j < m)
        res.push_back(b[j++]);
    return res;
}

struct SEGMENT_TREE{
    vector<vector<int>> st;
    inline SEGMENT_TREE(int n, vector<int>& vec){
        st.resize(4 * n);
        build(1, 0, n - 1, vec);
    }
    inline void build(int ind, int l, int r, vector<int>& vec){
        if (l == r){
            st[ind].push_back(vec[l]);
            return;
        }
        int mid = (l + r) >> 1;
        build(ind << 1, l, mid, vec);
        build(ind << 1 | 1, mid + 1, r, vec);
        st[ind] = st[ind << 1] + st[ind << 1 | 1];
        return;
    }
    inline long long get(int ind, int l, int r, int lb, int rb, int val){
        if (lb > rb) return 0;
        if (lb <= l && r <= rb){
            int it = upper_bound(st[ind].begin(), st[ind].end(), val) - st[ind].begin();
            return st[ind].size() - it;
        }
        int mid = (l + r) >> 1;
        long long ans = 0;
        if (mid >= lb) ans += get(ind << 1, l, mid, lb, rb, val);
        if (mid < rb) ans += get(ind << 1 | 1, mid + 1, r, lb, rb, val);
        return ans;
    }
};


inline long long count_swaps(vector<int> a){
    int n = a.size() / 2;
    long long res = 0;
    queue<int> q[2 * n + 1];
    vector<int> last_ind (a.size());

    for (int i = 0; i < a.size(); ++i){
        if (q[-a[i] + n].empty()){
            q[a[i] + n].push(i);
            last_ind[i] = i;
        }
        else{
            int pre = q[-a[i] + n].front();
            q[-a[i] + n].pop();
            last_ind[i] = pre;
        }
    }

    SEGMENT_TREE seg((int)a.size(), last_ind);
    for (int i = 0; i < a.size(); ++i) if (last_ind[i] != i){
        res += seg.get(1, 0, a.size() - 1, last_ind[i] + 1, i - 1, last_ind[i]);
        if (a[last_ind[i]] > 0) res++;
    }

    return res;
}

Compilation message (stderr)

/usr/bin/ld: /tmp/ccHhz2x2.o: in function `main':
grader.cpp:(.text.startup+0x26b): undefined reference to `count_swaps(std::vector<int, std::allocator<int> >)'
collect2: error: ld returned 1 exit status