Submission #85926

#	Time	Username	Problem	Language	Result	Execution time	Memory
85926		qkxwsm	Wild Boar (JOI18_wild_boar)	C++14	62 / 100	18109 ms	514100 KiB

wild_boar

#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>
void 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 DBG(x) cerr << #x << " = " << x << endl;
#define SZ(x) ((int) (x.size()))
#define FOR(i, a, b) for (auto i = (a); i < (b); i++)
#define FORD(i, a, b) for (auto i = (a) - 1; i >= (b); i--)
#define ALL(x) x.begin(), x.end()

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 8013
#define MAXK 100013

typedef long long ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef pair<ld, ld> pdd;
typedef vector<int> vi;
typedef vector<ll> vl;
typedef vector<ld> vd;
typedef vector<pii> vpi;
typedef vector<pll> vpl;
typedef vector<pdd> vpd;
typedef pair<pll, pll> ppp;

int N, M, Q, K, E = 2;
int arr[MAXK];
int to[MAXN], nxt[MAXN], head[MAXN];
ll len[MAXN];
ll ndist[MAXN / 4][MAXN / 4], dist[MAXN][MAXN];
int go[MAXN / 4][MAXN / 4];
ll dp[MAXN];
ll ans;

void addedge(int u, int v, ll d)
{
	if (u == v) return;
	to[E] = v;
	nxt[E] = head[u];
	head[u] = E;
	len[E] = d;
	E++;
	to[E] = u;
	nxt[E] = head[v];
	head[v] = E;
	len[E] = d;
	E++;
}
void solve()
{
	FOR(i, 0, E)
	{
		dp[i] = LLINF;
	}
	dp[head[arr[0] + N]] = 0;
	FOR(i, 0, K - 1)
	{
		int u = arr[i], v = arr[i + 1];
		ppp opt = MP(MP(LLINF, LLINF), MP(LLINF, LLINF));
		for (int s = head[u]; s; s = nxt[s])
		{
			pll cur = MP(dp[s ^ 1], s);
			if (cur < opt.fi)
			{
				opt.se = opt.fi;
				opt.fi = cur;
			}
			else if (cur < opt.se)
			{
				opt.se = cur;
			}
			dp[s ^ 1] = LLINF;
		}
		for (int t = head[v]; t; t = nxt[t])
		{
			if (opt.fi.se != LLINF)
			ckmin(dp[t ^ 1], opt.fi.fi + dist[opt.fi.se ^ 1][t ^ 1]);
			if (opt.se.se != LLINF)
			ckmin(dp[t ^ 1], opt.se.fi + dist[opt.se.se ^ 1][t ^ 1]);
		}
		// for (int s = head[u]; s; s = nxt[s])
		// {
		// 	for (int t = head[v]; t; t = nxt[t])
		// 	{
		// 		ckmin(dp[t ^ 1], dp[s ^ 1] + dist[s ^ 1][t ^ 1]);
		// 	}
		// 	dp[s ^ 1] = LLINF;
		// }
		//find the one with minimum dist[s ^ 1][t ^ 1], then the rest all have the same one!
	}
	ans = LLINF;
	for (int s = head[arr[K - 1]]; s; s = nxt[s])
	{
		ckmin(ans, dp[s ^ 1]);
	}
	ans = (ans == LLINF ? -1 : ans);
}

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);
	cin >> N >> M >> Q >> K;
	FOR(i, 0, M)
	{
		int u, v; ll d;
		cin >> u >> v >> d;
		u--; v--;
		addedge(u, v, d);
	}
	FOR(i, 0, N)
	{
		addedge(i, i + N, 0);
	}
	FOR(u, 0, 2 * N)
	{
		for (int s = head[u]; s; s = nxt[s])
		{
			priority_queue<pll, vector<pll>, greater<pll> > pq;
			FOR(i, 0, E)
			{
				dist[s][i] = LLINF;
			}
			dist[s][s] = 0;
			pq.push(MP(0, s));
			while(!pq.empty())
			{
				ll d = pq.top().fi; int ed = pq.top().se;
				pq.pop();
				for (int ed1 = head[to[ed]]; ed1; ed1 = nxt[ed1])
				{
					if ((ed1 xor ed) == 1) continue;
					// cerr << ed << " to " << ed1 << endl;
					// cerr << d + len[ed1] << " cmp " << dist[s][ed1] << endl;
					if (dist[s][ed1] > d + len[ed1])
					{
						dist[s][ed1] = d + len[ed1];
						pq.push(MP(dist[s][ed1], ed1));
					}
				}
			}
		}
	}
	// FOR(i, 2, E)
	// {
	// 	FOR(j, 2, E)
	// 	{
	// 		cerr << (dist[i][j] == LLINF ? -1 : dist[i][j]) << ' ';
	// 	}
	// 	cerr << endl;
	// }
	//a vertex numbered (i, j) means you're at j, but you just came from i
	FOR(i, 0, K)
	{
		cin >> arr[i];
		arr[i]--;
	}
	FOR(i, 0, Q)
	{
		int qid, qv;
		cin >> qid >> qv;
		qid--; qv--;
		arr[qid] = qv;
		solve();
		cout << ans << '\n';
	}
	// cerr << "time elapsed = " << (clock() / (CLOCKS_PER_SEC / 1000)) << " ms" << endl;
	return 0;
}

• Subtask 1: 12 / 12
• Subtask 2: 35 / 35
• Subtask 3: 15 / 15
• Subtask 4: 0 / 38