oj.uz

Submission #969097

# Submission time Handle Problem Language Result Execution time Memory
969097 2024-04-24T13:38:30 Z GrindMachine Simurgh (IOI17_simurgh) C++17
100 / 100
 123 ms 6172 KB 
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
 
using namespace std;
using namespace __gnu_pbds;
 
template<typename T> using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
typedef long long int ll;
typedef long double ld;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
 
#define fastio ios_base::sync_with_stdio(false); cin.tie(NULL)
#define pb push_back
#define endl '\n'
#define sz(a) (int)a.size()
#define setbits(x) __builtin_popcountll(x)
#define ff first
#define ss second
#define conts continue
#define ceil2(x,y) ((x+y-1)/(y))
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define yes cout << "Yes" << endl
#define no cout << "No" << endl
 
#define rep(i,n) for(int i = 0; i < n; ++i)
#define rep1(i,n) for(int i = 1; i <= n; ++i)
#define rev(i,s,e) for(int i = s; i >= e; --i)
#define trav(i,a) for(auto &i : a)
 
template<typename T>
void amin(T &a, T b) {
    a = min(a,b);
}
 
template<typename T>
void amax(T &a, T b) {
    a = max(a,b);
}
 
#ifdef LOCAL
#include "debug.h"
#else
#define debug(x) 42
#endif
 
/*
 
refs:
https://codeforces.com/blog/entry/53595?#comment-376568
 
*/
 
const int MOD = 1e9 + 7;
const int N = 500 + 5;
const int inf1 = int(1e9) + 5;
const ll inf2 = ll(1e18) + 5;
 
#include "simurgh.h"

struct DSU {
    vector<int> par, rankk, siz;

    DSU() {

    }

    DSU(int n) {
        init(n);
    }

    void init(int n) {
        par = vector<int>(n + 1);
        rankk = vector<int>(n + 1);
        siz = vector<int>(n + 1);
        rep(i, n + 1) create(i);
    }

    void create(int u) {
        par[u] = u;
        rankk[u] = 0;
        siz[u] = 1;
    }

    int find(int u) {
        if (u == par[u]) return u;
        else return par[u] = find(par[u]);
    }

    bool same(int u, int v) {
        return find(u) == find(v);
    }

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

        if (rankk[u] == rankk[v]) rankk[u]++;
        if (rankk[u] < rankk[v]) swap(u, v);

        par[v] = u;
        siz[u] += siz[v];
    }
};

int f(vector<int> v){
	return count_common_roads(v);
}

vector<pii> adj[N];
vector<int> ord;
vector<int> tin(N);
vector<pii> low(N);
vector<bool> vis(N);
int timer = 1;
vector<int> spanning;
vector<pii> par(N);

void dfs1(int u, int p){
	vis[u] = 1;
	tin[u] = timer++;
	low[u] = {tin[u],-1};

	for(auto [v,id] : adj[u]){
		if(v == p) conts;
		if(vis[v]){
			amin(low[u],{tin[v],id});
		}
		else{
			spanning.pb(id);
			par[v] = {u,id};
			dfs1(v,u);
			amin(low[u],low[v]);
		}
	}

	ord.pb(u);
}

std::vector<int> find_roads(int n, std::vector<int> U, std::vector<int> V) {
	int m = sz(U);
	rep(i,m){
		int u = U[i], v = V[i];
		adj[u].pb({v,i}), adj[v].pb({u,i});
	}

	dfs1(0,-1);

	vector<int> status(m,-1);
	int original = f(spanning);

	trav(u,ord){
		// find the val of the incoming span edge
		if(!u) conts;
		auto [p,pid] = par[u];
		if(low[u].ff > tin[p]){
			status[pid] = 1;
			conts;
		}
		if(status[pid] != -1) conts;

		int cyc_id = low[u].ss;
		int x = U[cyc_id], y = V[cyc_id];
		if(tin[x] < tin[y]) swap(x,y);
		vector<int> pending;

		while(x != y){
			auto [p,pid] = par[x];
			if(status[pid] != -1){
				auto curr = spanning;
				curr.erase(find(all(curr),pid));
				curr.pb(cyc_id);
				int val = f(curr);
				int cyc_status = val+status[pid]-original;
				
				if(!count(all(pending),par[u].ss)){
					pending.pb(par[u].ss);
				}

				while(!pending.empty()){
					int edge_id = pending.back();
					pending.pop_back();
					curr = spanning;
					curr.erase(find(all(curr),edge_id));
					curr.pb(cyc_id);
					val = f(curr);
					status[edge_id] = original+cyc_status-val;
				}

				break;
			}

			x = p;
			pending.pb(pid);
		}

		if(pending.empty()) conts;

		// full cycle, none known
		pending.pb(cyc_id);
		auto curr = spanning;
		curr.pb(cyc_id);
		map<int,vector<int>> mp;

		trav(id,pending){
			curr.erase(find(all(curr),id));
			int val_without = f(curr);
			curr.pb(id);
			mp[val_without].pb(id);
		}

		if(sz(mp) == 1){
			// all 0
			trav(id,pending){
				status[id] = 0;
			}
		}
		else{
			assert(sz(mp) == 2);
			trav(id,mp.begin()->second){
				status[id] = 1;
			}
			trav(id,(--mp.end())->second){
				status[id] = 0;
			}
		}
	}

	auto get = [&](vector<int> edges){
		// edges form a star at some node u
		DSU dsu(n);
		trav(id,edges){
			dsu.merge(U[id],V[id]);
		}

		auto curr = edges;
		int extra = 0;

		trav(id,spanning){
			int u = U[id], v = V[id];
			if(dsu.same(u,v)) conts;
			dsu.merge(u,v);
			extra += status[id];
			curr.pb(id);
		}

		int val = f(curr);
		return val-extra;
	};

	// find the status of all non-tree adj edges to u (s.t u < v)
	rep(u,n){
		vector<int> edges;
		for(auto [v,id] : adj[u]){
			if(status[id] != -1) conts;
			if(v < u) conts;
			edges.pb(id);
		}

		while(!edges.empty()){
			if(!get(edges)) break;
			int l = 0, r = sz(edges)-1;
			int first = -1;
			while(l <= r){
				int mid = (l+r) >> 1;
				vector<int> curr_edges;
				rep(i,mid+1) curr_edges.pb(edges[i]);
				
				if(get(curr_edges)){
					first = mid;
					r = mid-1;
				}
				else{
					l = mid+1;
				}
			}

			assert(first != -1);

			vector<int> nxt_edges;
			rep(i,sz(edges)){
				if(i < first){
					status[edges[i]] = 0;
				}
				else if(i == first){
					status[edges[i]] = 1;
				}
				else{
					nxt_edges.pb(edges[i]);
				}
			}

			edges = nxt_edges;
		}
	}

	vector<int> ans;
	rep(i,m){
		if(status[i] == 1){
			ans.pb(i);
		}
	}

	return ans;
}

Subtask #1
13.0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB correct
2 Correct 0 ms 348 KB correct
3 Correct 0 ms 348 KB correct
4 Correct 1 ms 348 KB correct
5 Correct 0 ms 348 KB correct
6 Correct 1 ms 348 KB correct
7 Correct 0 ms 348 KB correct
8 Correct 1 ms 348 KB correct
9 Correct 0 ms 348 KB correct
10 Correct 0 ms 348 KB correct
11 Correct 1 ms 344 KB correct
12 Correct 0 ms 348 KB correct
13 Correct 0 ms 348 KB correct

Subtask #2
17.0 / 17.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB correct
2 Correct 0 ms 348 KB correct
3 Correct 0 ms 348 KB correct
4 Correct 1 ms 348 KB correct
5 Correct 0 ms 348 KB correct
6 Correct 1 ms 348 KB correct
7 Correct 0 ms 348 KB correct
8 Correct 1 ms 348 KB correct
9 Correct 0 ms 348 KB correct
10 Correct 0 ms 348 KB correct
11 Correct 1 ms 344 KB correct
12 Correct 0 ms 348 KB correct
13 Correct 0 ms 348 KB correct
14 Correct 1 ms 348 KB correct
15 Correct 1 ms 348 KB correct
16 Correct 1 ms 348 KB correct
17 Correct 1 ms 348 KB correct
18 Correct 1 ms 348 KB correct
19 Correct 2 ms 348 KB correct
20 Correct 1 ms 348 KB correct
21 Correct 1 ms 348 KB correct
22 Correct 1 ms 348 KB correct
23 Correct 1 ms 348 KB correct
24 Correct 1 ms 348 KB correct
25 Correct 1 ms 348 KB correct
26 Correct 1 ms 348 KB correct
27 Correct 1 ms 348 KB correct
28 Correct 1 ms 348 KB correct
29 Correct 1 ms 348 KB correct
30 Correct 1 ms 348 KB correct
31 Correct 1 ms 348 KB correct
32 Correct 1 ms 348 KB correct
33 Correct 1 ms 348 KB correct

Subtask #3
21.0 / 21.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB correct
2 Correct 0 ms 348 KB correct
3 Correct 0 ms 348 KB correct
4 Correct 1 ms 348 KB correct
5 Correct 0 ms 348 KB correct
6 Correct 1 ms 348 KB correct
7 Correct 0 ms 348 KB correct
8 Correct 1 ms 348 KB correct
9 Correct 0 ms 348 KB correct
10 Correct 0 ms 348 KB correct
11 Correct 1 ms 344 KB correct
12 Correct 0 ms 348 KB correct
13 Correct 0 ms 348 KB correct
14 Correct 1 ms 348 KB correct
15 Correct 1 ms 348 KB correct
16 Correct 1 ms 348 KB correct
17 Correct 1 ms 348 KB correct
18 Correct 1 ms 348 KB correct
19 Correct 2 ms 348 KB correct
20 Correct 1 ms 348 KB correct
21 Correct 1 ms 348 KB correct
22 Correct 1 ms 348 KB correct
23 Correct 1 ms 348 KB correct
24 Correct 1 ms 348 KB correct
25 Correct 1 ms 348 KB correct
26 Correct 1 ms 348 KB correct
27 Correct 1 ms 348 KB correct
28 Correct 1 ms 348 KB correct
29 Correct 1 ms 348 KB correct
30 Correct 1 ms 348 KB correct
31 Correct 1 ms 348 KB correct
32 Correct 1 ms 348 KB correct
33 Correct 1 ms 348 KB correct
34 Correct 23 ms 1628 KB correct
35 Correct 23 ms 1628 KB correct
36 Correct 20 ms 1624 KB correct
37 Correct 6 ms 348 KB correct
38 Correct 23 ms 1812 KB correct
39 Correct 21 ms 1628 KB correct
40 Correct 20 ms 1372 KB correct
41 Correct 22 ms 1628 KB correct
42 Correct 22 ms 1628 KB correct
43 Correct 10 ms 1116 KB correct
44 Correct 9 ms 860 KB correct
45 Correct 9 ms 1112 KB correct
46 Correct 9 ms 860 KB correct
47 Correct 6 ms 604 KB correct
48 Correct 2 ms 348 KB correct
49 Correct 4 ms 348 KB correct
50 Correct 6 ms 604 KB correct
51 Correct 10 ms 920 KB correct
52 Correct 9 ms 860 KB correct
53 Correct 9 ms 860 KB correct
54 Correct 10 ms 1116 KB correct
55 Correct 9 ms 1112 KB correct
56 Correct 9 ms 1116 KB correct
57 Correct 9 ms 1116 KB correct

Subtask #4
19.0 / 19.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 348 KB correct
2 Correct 0 ms 348 KB correct
3 Correct 68 ms 3888 KB correct
4 Correct 107 ms 5220 KB correct
5 Correct 111 ms 5212 KB correct
6 Correct 102 ms 5212 KB correct
7 Correct 94 ms 5036 KB correct
8 Correct 96 ms 5212 KB correct
9 Correct 111 ms 5196 KB correct
10 Correct 108 ms 5212 KB correct
11 Correct 108 ms 5200 KB correct
12 Correct 109 ms 5400 KB correct
13 Correct 0 ms 348 KB correct
14 Correct 100 ms 5212 KB correct
15 Correct 123 ms 5240 KB correct

Subtask #5
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB correct
2 Correct 0 ms 348 KB correct
3 Correct 0 ms 348 KB correct
4 Correct 1 ms 348 KB correct
5 Correct 0 ms 348 KB correct
6 Correct 1 ms 348 KB correct
7 Correct 0 ms 348 KB correct
8 Correct 1 ms 348 KB correct
9 Correct 0 ms 348 KB correct
10 Correct 0 ms 348 KB correct
11 Correct 1 ms 344 KB correct
12 Correct 0 ms 348 KB correct
13 Correct 0 ms 348 KB correct
14 Correct 1 ms 348 KB correct
15 Correct 1 ms 348 KB correct
16 Correct 1 ms 348 KB correct
17 Correct 1 ms 348 KB correct
18 Correct 1 ms 348 KB correct
19 Correct 2 ms 348 KB correct
20 Correct 1 ms 348 KB correct
21 Correct 1 ms 348 KB correct
22 Correct 1 ms 348 KB correct
23 Correct 1 ms 348 KB correct
24 Correct 1 ms 348 KB correct
25 Correct 1 ms 348 KB correct
26 Correct 1 ms 348 KB correct
27 Correct 1 ms 348 KB correct
28 Correct 1 ms 348 KB correct
29 Correct 1 ms 348 KB correct
30 Correct 1 ms 348 KB correct
31 Correct 1 ms 348 KB correct
32 Correct 1 ms 348 KB correct
33 Correct 1 ms 348 KB correct
34 Correct 23 ms 1628 KB correct
35 Correct 23 ms 1628 KB correct
36 Correct 20 ms 1624 KB correct
37 Correct 6 ms 348 KB correct
38 Correct 23 ms 1812 KB correct
39 Correct 21 ms 1628 KB correct
40 Correct 20 ms 1372 KB correct
41 Correct 22 ms 1628 KB correct
42 Correct 22 ms 1628 KB correct
43 Correct 10 ms 1116 KB correct
44 Correct 9 ms 860 KB correct
45 Correct 9 ms 1112 KB correct
46 Correct 9 ms 860 KB correct
47 Correct 6 ms 604 KB correct
48 Correct 2 ms 348 KB correct
49 Correct 4 ms 348 KB correct
50 Correct 6 ms 604 KB correct
51 Correct 10 ms 920 KB correct
52 Correct 9 ms 860 KB correct
53 Correct 9 ms 860 KB correct
54 Correct 10 ms 1116 KB correct
55 Correct 9 ms 1112 KB correct
56 Correct 9 ms 1116 KB correct
57 Correct 9 ms 1116 KB correct
58 Correct 1 ms 348 KB correct
59 Correct 0 ms 348 KB correct
60 Correct 68 ms 3888 KB correct
61 Correct 107 ms 5220 KB correct
62 Correct 111 ms 5212 KB correct
63 Correct 102 ms 5212 KB correct
64 Correct 94 ms 5036 KB correct
65 Correct 96 ms 5212 KB correct
66 Correct 111 ms 5196 KB correct
67 Correct 108 ms 5212 KB correct
68 Correct 108 ms 5200 KB correct
69 Correct 109 ms 5400 KB correct
70 Correct 0 ms 348 KB correct
71 Correct 100 ms 5212 KB correct
72 Correct 123 ms 5240 KB correct
73 Correct 1 ms 344 KB correct
74 Correct 107 ms 6172 KB correct
75 Correct 104 ms 6036 KB correct
76 Correct 55 ms 2648 KB correct
77 Correct 108 ms 5972 KB correct
78 Correct 109 ms 6148 KB correct
79 Correct 108 ms 5980 KB correct
80 Correct 118 ms 6044 KB correct
81 Correct 91 ms 5464 KB correct
82 Correct 108 ms 5904 KB correct
83 Correct 81 ms 3420 KB correct
84 Correct 46 ms 4188 KB correct
85 Correct 45 ms 3928 KB correct
86 Correct 37 ms 2648 KB correct
87 Correct 34 ms 2136 KB correct
88 Correct 29 ms 1628 KB correct
89 Correct 30 ms 1628 KB correct
90 Correct 31 ms 1628 KB correct
91 Correct 14 ms 600 KB correct
92 Correct 7 ms 348 KB correct
93 Correct 53 ms 4108 KB correct
94 Correct 36 ms 2648 KB correct
95 Correct 38 ms 2812 KB correct
96 Correct 29 ms 1624 KB correct
97 Correct 32 ms 1760 KB correct
98 Correct 32 ms 2396 KB correct
99 Correct 35 ms 1628 KB correct
100 Correct 20 ms 604 KB correct
101 Correct 9 ms 344 KB correct
102 Correct 38 ms 3164 KB correct
103 Correct 45 ms 3772 KB correct
104 Correct 38 ms 3340 KB correct
105 Correct 38 ms 3344 KB correct