Submission #79874

#	Time	Username	Problem	Language	Result	Execution time	Memory
79874		qkxwsm	Travelling Merchant (APIO17_merchant)	C++14	100 / 100	97 ms	14616 KiB

merchant

/*
    _____
  .'     '.
 /  0   0  \
|     ^     |
|  \     /  |
 \  '---'  /
  '._____.'
*/
#pragma GCC optimize ("O3")
#pragma GCC target ("sse4")
#include <bits/stdc++.h>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/rope>

using namespace std;
using namespace __gnu_pbds;
using namespace __gnu_cxx;

random_device(rd);
mt19937 rng(rd());
const long long FIXED_RANDOM = chrono::steady_clock::now().time_since_epoch().count();

struct custom_hash
{
	template<class T>
    unsigned long long operator()(T v) const
	{
		unsigned long long x = v;
		x += FIXED_RANDOM; x += 11400714819323198485ull;
        x = (x ^ (x >> 30)) * 13787848793156543929ull;
        x = (x ^ (x >> 27)) * 10723151780598845931ull;
        return x ^ (x >> 31);
    }
};

template<class T> using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
template<class T, class U> using hash_table = gp_hash_table<T, U, custom_hash>;

template<class T>
void readi(T &x)
{
	x = 0;
	bool negative = false;
	char c = ' ';
	while (c < '-')
	{
		c = getchar();
	}
	if (c == '-')
	{
		negative = true;
		c = getchar();
	}
	while (c >= '0')
	{
		x = x * 10 + (c - '0');
		c = getchar();
	}
	if (negative)
	{
		x = -x;
	}
}
template<class T>
void printi(T output)
{
	if (output == 0)
	{
		putchar('0');
		return;
	}
	if (output < 0)
	{
		putchar('-');
		output = -output;
	}
	int buf[20], n = 0;
	while(output)
	{
		buf[n] = ((output % 10));
		output /= 10;
		n++;
	}
	for (n--; n >= 0; n--)
	{
		putchar(buf[n] + '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);
}
long long expo(long long a, long long e, long long mod)
{
	return ((e == 0) ? 1 : ((expo(a * a % mod, e >> 1, mod)) * ((e & 1) ? a : 1) % mod));
}
template<class T, class U>
T nmod(T &x, U mod)
{
	if (x >= mod) x -= mod;
}
template<class T>
T gcd(T a, T b)
{
	return (b ? gcd(b, a % b) : a);
}
template<class T>
T randomize(T mod)
{
	return (uniform_int_distribution<T>(0, mod - 1))(rng);
}

#define y0 ___y0
#define y1 ___y1
#define MP make_pair
#define MT make_tuple
#define PB push_back
#define PF push_front
#define fi first
#define se second
#define debug(x) cerr << #x << " = " << x << endl;
#define sz(x) ((int) (x.size()))

const long double PI = 4.0 * atan(1.0);
const long double EPS = 1e-9;

#define MAGIC 347
#define SINF 10007
#define CO 1000007
#define INF 1000000007
#define BIG 1000000931
#define LARGE 1696969696967ll
#define GIANT 2564008813937411ll
#define LLINF 2696969696969696969ll
#define MAXN 113
#define MAXK 1013

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, M, K;
vector<pair<ll, int> > edge[MAXN];
ll sell[MAXN][MAXK], buy[MAXN][MAXK];
ll dist[MAXN][MAXN], profit[MAXN][MAXN];
ll dp[MAXN][MAXN];

bool check(ll k)
{
	//earn / dist >= k => earn >= dist * k => earn - dist * k >= 0
	for (int i = 0; i < N; i++)
	{
		for (int j = 0; j < N; j++)
		{
			dp[i][j] = -LLINF;
			if (i == j || dist[i][j] == LLINF || profit[i][j] == -LLINF) continue;
			dp[i][j] = profit[i][j] - dist[i][j] * k;
		}
	}
	for (int k = 0; k < N; k++)
	{
		for (int i = 0; i < N; i++)
		{
			for (int j = 0; j < N; j++)
			{
				ckmax(dp[i][j], dp[i][k] + dp[k][j]);
			}
		}
	}
	for (int i = 0; i < N; i++)
	{
		if (dp[i][i] >= 0)
		{
			return true;
		}
	}
	return false;
}

int32_t main()
{
	// ios_base::sync_with_stdio(0); cin.tie(0);
	// cout << fixed << setprecision(10);
	// cerr << fixed << setprecision(10);
	// freopen ("file.in", "r", stdin);
	// freopen ("file.out", "w", stdout);
	readi(N); readi(M); readi(K);
	for (int i = 0; i < N; i++)
	{
		for (int j = 0; j < K; j++)
		{
			readi(buy[i][j]); readi(sell[i][j]); //buy, sell
			if (buy[i][j] == -1) buy[i][j] = LLINF;
			if (sell[i][j] == -1) sell[i][j] = -LLINF;
		}
	}
	for (int i = 0; i < N; i++)
	{
		for (int j = 0; j < N; j++)
		{
			dist[i][j] = LLINF;
			profit[i][j] = 0;
		}
		dist[i][i] = 0;
	}
	for (int i = 0; i < M; i++)
	{
		int u, v; ll d;
		readi(u); readi(v); readi(d); u--; v--;
		ckmin(dist[u][v], d);
	}
	for (int k = 0; k < N; k++)
	{
		for (int i = 0; i < N; i++)
		{
			for (int j = 0; j < N; j++)
			{
				ckmin(dist[i][j], dist[i][k] + dist[k][j]);
			}
		}
	}
	for (int i = 0; i < N; i++)
	{
		for (int j = 0; j < N; j++)
		{
			for (int k = 0; k < K; k++)
			{
				ckmax(profit[i][j], sell[j][k] - buy[i][k]);
			}
			// cerr << profit[i][j] << ' ';
		}
		// cerr << endl;
	}
	// for (int i = 0; i < N; i++)
	// {
	// 	for (int j = 0; j < N; j++)
	// 	{
	// 		cerr << profit[i][j] << ' ';
	// 	}
	// 	cerr << endl;
	// }
	// for (int i = 0; i < N; i++)
	// {
	// 	for (int j = 0; j < N; j++)
	// 	{
	// 		cerr << dist[i][j] << ' ';
	// 	}
	// 	cerr << endl;
	// }
	//for every pair (u, v) calculate minimum distance and maximum profit
	ll lo = 0, hi = INF;
	while(hi > lo)
	{
		int mid = (hi + lo + 1) >> 1;
		if (check(mid))
		{
			lo = mid;
		}
		else
		{
			hi = mid - 1;
		}
	}
	printi(lo); putchar('\n');
	// cerr << "time elapsed = " << (clock() / (CLOCKS_PER_SEC / 1000)) << " ms" << endl;
	return 0;
}

• Subtask 1: 12 / 12
• Subtask 2: 21 / 21
• Subtask 3: 33 / 33
• Subtask 4: 34 / 34