Submission #251254

#	Time	Username	Problem	Language	Result	Execution time	Memory
251254		_7_7_	Bridges (APIO19_bridges)	C++14	100 / 100	2341 ms	5512 KiB

bridges

#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;

//#define int long long
//#pragma GCC optimize("Ofast")
//#pragma comment(linker, "/stack:200000000")
//#pragma GCC target("sse,sse2,sse3,ssse3,sse4")
 
 
#define file(s) freopen(s".in","r",stdin); freopen(s".out","w",stdout);
#define fastio ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
#define all(x) x.begin(), x.end()
#define sz(s) (int)s.size()
#define pb push_back
#define ppb pop_back
#define mp make_pair
#define s second
#define f first
 
 

 
 
typedef pair < int, int > pii;
typedef unsigned long long ull;         
typedef vector < pii > vpii;
typedef vector < int > vi;
typedef long double ldb;  
typedef long long ll;  
typedef double db;                             
 
typedef tree<pii, null_type, less<pii>, rb_tree_tag, tree_order_statistics_node_update> ordered_set;
 
const int dx[] = {1, -1, 0, 0}, dy[] = {0, 0, 1, -1}, block = 1055;
const int inf = 1e9, maxn = 4e5 + 148, mod = 1e9 + 7, N = 1e5 + 11;
const pii base = mp(1171, 3307), Mod = mp(1e9 + 7, 1e9 + 9);
const db eps = 1e-12, pi = 3.14159265359;
const ll INF = 1e18;

int timer;
struct DSU {
	int p[N], cnt[N];
	stack < int > st;

	void init (int n) {
		for (int i = 1; i <= n; ++i) {
			p[i] = i;
			cnt[i] = 1;
		}

		while (sz(st))
			st.pop();
	}	
	int get (int v) { 
		return p[v] == v ? v : get(p[v]);
	}

	void merge (int v, int u) {
		v = get(v), u = get(u);
		if (v == u)
			return;

		if (cnt[v] < cnt[u])
			swap(v, u);   	
		st.push(u);
		p[u] = v;
		cnt[v] += cnt[u];
		++timer;
	}

	void undo () {
		int u = st.top();
		int v = p[u];
		st.pop();
		p[u] = u;
		cnt[v] -= cnt[u];
	}
} T;


vi nw;
vpii prv;
bool was[N];
vector < pair < pii, int > > a, b;
int n, m, q, v[N], u[N], w[N], tp, x, y, ww[N], res[N];

main () {
	fastio
	scanf("%d%d", &n, &m);
	for (int i = 1; i <= m; ++i) 
		scanf("%d%d%d", &v[i], &u[i], &w[i]);
	
	scanf("%d", &q);
	for (int i = 1; i <= q; ++i) {
		scanf("%d%d%d", &tp, &x, &y);	
		if (tp == 1) 
			a.pb({{x, y}, i});
		else
			b.pb({{y, x}, i});

		if (i % block == 0 || i == q) {
			T.init(n);
			for (int i = 1; i <= m; ++i)
				was[i] = 0;

			for (auto x : a)
				was[x.f.f] = 1;
			sort(all(b));
			reverse(all(b));
			for (int i = 1; i <= m; ++i)
				if (!was[i])
					prv.pb({w[i], i});
				else
					nw.pb(i);	

			sort(all(prv));
			reverse(all(prv));
			int j = 0;

			for (auto x : b) {
				while (j < sz(prv) && prv[j].f >= x.f.f) {
					T.merge(v[prv[j].s], u[prv[j].s]);
					++j;
				}

				for (auto y : nw)
					ww[y] = w[y];

				for (auto y : a)
					if (y.s <= x.s)
						ww[y.f.f] = y.f.s;

				timer = 0;
				for (auto y : nw)
					if (ww[y] >= x.f.f)
						T.merge(v[y], u[y]);

				res[x.s] = T.cnt[T.get(x.f.s)];
				while (timer--)
					T.undo();
			}
			
			for (auto y : a)
				w[y.f.f] = y.f.s;
			
			a.clear();
			b.clear();
			nw.clear();
			prv.clear();	
		}
	}
	
	for (int i = 1; i <= q; ++i)
		if (res[i])
			printf("%d\n", res[i]);
}

Compilation message (stderr)

bridges.cpp:92:7: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
 main () {
       ^
bridges.cpp: In function 'int main()':
bridges.cpp:94:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%d", &n, &m);
  ~~~~~^~~~~~~~~~~~~~~~
bridges.cpp:96:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d%d%d", &v[i], &u[i], &w[i]);
   ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
bridges.cpp:98:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d", &q);
  ~~~~~^~~~~~~~~~
bridges.cpp:100:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d%d%d", &tp, &x, &y); 
   ~~~~~^~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 13 / 13
• Subtask 2: 16 / 16
• Subtask 3: 17 / 17
• Subtask 4: 14 / 14
• Subtask 5: 13 / 13
• Subtask 6: 27 / 27