Submission #63486

#	Time	Username	Problem	Language	Result	Execution time	Memory
63486		qkxwsm	Palembang Bridges (APIO15_bridge)	C++17	22 / 100	51 ms	5212 KiB

bridge

/*
PROG: source
LANG: C++11
    _____
  .'     '.
 /  0   0  \
|     ^     |
|  \     /  |
 \  '---'  /
  '._____.'
*/
#include <bits/stdc++.h>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/pb_ds/assoc_container.hpp>

using namespace std;
using namespace __gnu_pbds;

struct chash
{
        int operator()(int x) const
        {
                x ^= (x >> 20) ^ (x >> 12);
                return x ^ (x >> 7) ^ (x >> 4);
        }
        int operator()(long long x) const
        {
                return x ^ (x >> 32);
        }
};

template<typename T> using orderedset = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
template<typename T, typename U> using hashtable = gp_hash_table<T, U, chash>;

template<class T>
void readi(T &x)
{
	T input = 0;
	bool negative = false;
	char c = ' ';
	while (c < '-')
        {
		c = getchar();
	}
	if (c == '-')
	{
		negative = true;
		c = getchar();
	}
	while (c >= '0')
	{
		input = input * 10 + (c - '0');
		c = getchar();
	}
	if (negative)
	{
		input = -input;
	}
	x = input;
}
template<class T>
void printi(T output)
{
	if (output == 0)
	{
		putchar('0');
		return;
	}
	if (output < 0)
	{
		putchar('-');
		output = -output;
	}
	int aout[20];
	int ilen = 0;
	while(output)
	{
		aout[ilen] = ((output % 10));
		output /= 10;
		ilen++;
	}
	for (int i = ilen - 1; i >= 0; i--)
	{
		putchar(aout[i] + '0');
	}
	return;
}
template<class T>
void ckmin(T &a, T b)
{
	a = min(a, b);
}
template<class T>
void ckmax(T &a, T b)
{
	a = max(a, b);
}
template<class T, class U>
T normalize(T x, U mod = 1000000007)
{
	return (((x % mod) + mod) % mod);
}
long long randomizell(long long mod)
{
	return ((1ll << 45) * rand() + (1ll << 30) * rand() + (1ll << 15) * rand() + rand()) % mod;
}
int randomize(int mod)
{
	return ((1ll << 15) * rand() + rand()) % mod;
}

#define y0 ___y0
#define y1 ___y1
#define MP make_pair
#define MT make_tuple
#define PB push_back
#define PF push_front
#define LB lower_bound
#define UB upper_bound
#define fi first
#define se second
#define debug(x) cerr << #x << " = " << x << endl;

const long double PI = 4.0 * atan(1.0);
const long double EPS = 1e-10;

#define MAGIC 347
#define SINF 10007
#define CO 1000007
#define INF 1000000007
#define BIG 1000000931
#define LARGE 1696969696967ll
#define GIANT 2564008813937411ll
#define LLINF 2696969696969696969ll

typedef long long ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef pair<ld, ld> pdd;

int N, K;
ll ans = 0, best = LLINF;
vector<pll> ranges;
vector<ll> pos;

bool cmp(pll a, pll b)
{
        return a.fi + a.se < b.fi + b.se;
}

ll f(ll a, ll b)
{
        ll res = 0;
        ll x = pos[a], y = pos[b];
        int lo = 0, hi = N - 1;
        while(hi > lo)
        {
                int mid = (hi + lo + 1) / 2;
                if (ranges[mid].fi + ranges[mid].se >= x + y)
                {
                        lo = mid;
                }
                else
                {
                        hi = mid - 1;
                }
        }
        for (int i = 0; i < lo; i++)
        {
                res += abs(x - ranges[i].fi) + abs(x - ranges[i].se);
        }
        for (int i = lo; i < N; i++)
        {
                res += abs(y - ranges[i].fi) + abs(y - ranges[i].se);
        }
        return res;
}

void solve(int L, int R, int optl, int optr)
{
        if (L > R)
        {
                return;
        }
        ll cur = LLINF;
        int mid = (L + R) / 2, opt = -1;
        for (int i = max(mid + 1, optl); i <= optr; i++)
        {
                if (f(mid, i) <= cur)
                {
                        opt = i;
                        cur = f(mid, i);
                }
        }
        ckmin(best, cur);
        solve(L, mid - 1, optl, opt);
        solve(mid + 1, R, opt, optr);
}

int32_t main()
{
	ios_base::sync_with_stdio(0);
	srand(time(0));
	//	cout << fixed << setprecision(10);
	//	cerr << fixed << setprecision(10);
	if (fopen("input.in", "r"))
	{
		freopen ("input.in", "r", stdin);
		freopen ("output.out", "w", stdout);
	}
// 1 5
// B 0 A 4
// B 1 B 3
// A 5 B 7
// B 2 A 6
// B 1 A 7
        cin >> K >> N;
        for (int i = 0; i < N; i++)
        {
                char c1; int x; char c2; int y;
                cin >> c1 >> x >> c2 >> y;
                if (c1 == 'B')
                {
                        swap(c1, c2);
                        swap(x, y);
                }
                if (c1 == c2)
                {
                        ans += abs(y - x);
                }
                else
                {
                        ranges.PB({x, y});
                        // cerr << x << ' ' << y << endl;
                }
        }
        N = ranges.size();
        if (N == 0)
        {
                cout << ans << '\n';
                return 0;
        }
        ans += N;
        if (K == 1 || N == 1)
        {
                vector<ll> v;
                for (pll x : ranges)
                {
                        v.PB(x.fi);
                        v.PB(x.se);
                }
                // for (int x : v)
                // {
                //         cerr << "lol " << x << endl;
                // }
                nth_element(v.begin(), v.begin() + (v.size() / 2) - 1, v.end());
                ll pos = v[v.size() / 2 - 1];
                for (ll x : v)
                {
                        ans += abs(pos - x);
                }
                cout << ans << '\n';
                return 0;
        }
        //now solve the problem
        //min|a-x|+|b-x|, |a-y|+|b-y|
        //it's clear you want to put at actual coordinates
        //for less than x, obviously you wanna go to x
        //x < a < b < y
        //a-x+b-x < y-a + y-b => 2(a+b)<(2x+2y) => (a+b) < (x+y)
        pos.reserve(2 * N);
        for (int i = 0; i < N; i++)
        {
                pos.PB(ranges[i].fi);
                pos.PB(ranges[i].se);
        }
        sort(pos.begin(), pos.end());
        pos.erase(unique(pos.begin(), pos.end()), pos.end());
        sort(ranges.begin(), ranges.end(), cmp);
        // ll best = LLINF;
        solve(0, pos.size() - 2, 1, pos.size() - 1);
        ans += best;
        cout << ans << '\n';
	//	cerr << "time elapsed = " << (clock() / (CLOCKS_PER_SEC / 1000)) << " ms" << endl;
	return 0;
}

Compilation message (stderr)

bridge.cpp: In function 'int32_t main()':
bridge.cpp:209:11: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   freopen ("input.in", "r", stdin);
   ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
bridge.cpp:210:11: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   freopen ("output.out", "w", stdout);
   ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 8 / 8
• Subtask 2: 14 / 14
• Subtask 3: 0 / 9
• Subtask 4: 0 / 32
• Subtask 5: 0 / 37