Submission #1193404

#	Time	Username	Problem	Language	Result	Execution time	Memory
1193404		yoshi	Arranging Shoes (IOI19_shoes)	C++20	Compilation error	0 ms	0 KiB

shoes

#include<bits/stdc++.h>
#define ll long long
#define pb push_back
#define ss second
#define ff first
using namespace std;
ll df[1234567],ans; 
vector<ll> vv[1234567];
struct segtree{
    ll n;
    vector<ll>d;
    segtree(ll n){
        d.resize(4*n);
        build(1,1,n);
    }
    void build(ll v, ll l, ll r){
        if(l == r){
            d[v] = 1;
            return;
        }
        ll m = (l+r)/2;
        build(v*2,l,m);
        build(v*2+1,m+1,r);
        d[v] = d[v*2]+d[v*2+1];
    }
    void update(ll v,ll l, ll r, ll pos, ll val){
        if(pos < l or pos > r)return;
        if(l == r){
            d[v] = val;
            return;
        }
        ll m = (l+r)/2;
        update(v*2,l,m,pos,val);
        update(v*2+1,m+1,r,pos,val);
        d[v] = d[v*2]+d[v*2+1];
    }
    ll query(ll v, ll l, ll r, ll L, ll R){
        if(R<L||R<l||r<L) return 0ll;
        if(L<=l&&r<=R) return d[v];
        ll m = (l+r)/2;
        return query(v*2,l,m,L,R) + query(v*2+1,m+1,r,L,R);
    }
};
int count_swaps(vector<int> a){
    int n = a.size() / 2;
    map<int, vector<int>> w;
    for(int i = 0; i < a.size(); ++i){
        w[a[i]].push_back(i + 1);
    }

    vector<pair<int,int>> v;
    int cnt = 0;
    for(auto& [key, vec] : w){
        if(key < 0) continue;
        auto& left = w[-key];
        auto& right = w[key];
        for(int i = 0; i < left.size(); ++i){
            if(left[i] < right[i]){
                v.push_back({left[i] + 1, right[i] - 1});
            } else {
                v.push_back({right[i] + 1, left[i] - 1});
                cnt++;
            }
        }
    }

    sort(v.begin(), v.end());
    segtree yo(2 * n);
    for(auto [l, r] : v){
        cnt += yo.query(1, 1, 2*n, l, r);
        yo.update(1, 1, 2*n, r + 1, 0);
    }

    return cnt;
}

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

Compilation message (stderr)

/usr/bin/ld: /tmp/cc736NJH.o: in function `main':
grader.cpp:(.text.startup+0x0): multiple definition of `main'; /tmp/cc5jNpbm.o:shoes.cpp:(.text.startup+0x0): first defined here
collect2: error: ld returned 1 exit status