Submission #469570

#	Time	Username	Problem	Language	Result	Execution time	Memory
469570		spike1236	Arranging Shoes (IOI19_shoes)	C++14	10 / 100	1084 ms	300 KiB

shoes

#include <bits/stdc++.h>
#include "shoes.h"
using namespace std;
#define pb push_back
#define mp make_pair
#define f first
#define s second
#define ll long long
#define ld long double
#define all(_v) _v.begin(), _v.end()
#define sz(_v) (int)_v.size()
#define pii pair <int, int>
#define pll pair <ll, ll>
#define veci vector <int>
#define vecll vector <ll>

const int dx[4] = {1, -1, 0, 0};
const int dy[4] = {0, 0, -1, 1};
const double PI = 3.1415926535897932384626433832795;
const double eps = 1e-9;
const int MOD1 = 1e9 + 7;
const int MOD2 = 998244353;

const int MAXN = 1e5 + 10;
int t[MAXN], n;
int pos[MAXN][2];

void upd(int r, int val) {
    for(; r <= 2 * n; r += (r & -r)) t[r] += val;
}

int get(int r) {
    int res = 0;
    for(; r > 0; r -= (r & -r)) res += t[r];
    return res;
}

ll count_swaps(veci b) {
    n = sz(b) / 2;
    for(int i = 0; i < 2 * n; ++i) {
        upd(i + 1, 1);
        if(b[i] < 0) pos[-b[i]][0] = i + 1;
        else pos[b[i]][1] = i + 1;
    }
    ll ans = 0;
    vector <pii> seg;
    for(int i = 1; i <= n; ++i) {
        int l = pos[i][0], r = pos[i][1];
        if(l > r) ++ans, swap(l, r);
        seg.pb(mp(l, r));
        ///cout << l << ' ' << r << '\n';
    }
    sort(all(seg));
    for(auto p : seg) {
        int l = p.f, r = p.s;
        ans += get(r - 1) - get(l);
        upd(l, -1);
        upd(r, -1);
    }
    return ans;
}

void solve() {
    cout << count_swaps({2, 1, -1, -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