제출 #582021

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
582021		alireza_kaviani	Simurgh (IOI17_simurgh)	C++17	100 / 100	1953 ms	9400 KiB

simurgh

#include "simurgh.h"
#include <bits/stdc++.h>
using namespace std;

typedef long long ll;
typedef pair<int,int> pii;
typedef pair<ll, ll> pll;

#define SZ(x)	int((x).size())
#define X 		first
#define Y 		second
#define sep 	' '

const ll MAXN = 510; //TODO: fix MAXN

int n , m , common , mark[MAXN] , H[MAXN] , par[MAXN] , ind[MAXN] , tree[MAXN * MAXN] , ans[MAXN * MAXN];
vector<pii> E , adj[MAXN] , back_edge[MAXN];

int query(int A[]){
	vector<int> vec;
	for(int i = 0 ; i < m ; i++){
		if(A[i]){
			vec.push_back(i);
		}
	}
	//assert(SZ(vec) == n - 1);
	return count_common_roads(vec);
}

int query_back_edge(vector<pii> &v , int l , int r){
	assert(l > 0);
	int sum = common;
	for(int i = l ; i < r ; i++){
		tree[v[i].Y] = 1;
		tree[ind[v[i - 1].X]] = 0;
		sum -= ans[ind[v[i - 1].X]];
	}
	int res = query(tree);
	for(int i = l ; i < r ; i++){
		tree[v[i].Y] = 0;
		tree[ind[v[i - 1].X]] = 1;
	}
	return res - sum;
}

void DFS(int v){
	mark[v] = 1;
	for(pii i : adj[v]){
		int u = i.X , w = i.Y;
		if(mark[u]){
			continue;
		}
		//cout << v << sep << u << sep << w << endl;
		par[u] = v;
		ind[u] = w;
		tree[w] = 1;
		H[u] = H[v] + 1;
		DFS(u);
	}
}

void Calc(int v , int u , int index){
	int mx = common , W = -1 , x = v , flag = 1;
	while(x != u){
		if(ans[ind[x]] == -1){
			flag = 0;
		}
		x = par[x];
	}
	if(flag){
		return;
	}
	vector<pii> res;
	tree[index] = 1;
	x = v;
	while(x != u){
		if(ans[ind[x]] != -1){
			if(W != -1){
				res.push_back({W - ans[ind[x]] , x});
				x = par[x];
				continue;
			}
			tree[ind[x]] = 0;
			int cur = query(tree);
			tree[ind[x]] = 1;
			res.push_back({cur , x});
			W = cur + ans[ind[x]];
			x = par[x];
			continue;
		}
		tree[ind[x]] = 0;
		int cur = query(tree);
		tree[ind[x]] = 1;
		res.push_back({cur , x});
		x = par[x];
	}
	tree[index] = 0;
	//cout << "==========" << endl;
	//cout << v << sep << u << sep << index << endl;
	for(pii i : res){
		//cout << i.X << sep << i.Y << endl;
		mx = max(mx , i.X);
	}
	for(pii i : res){
		if(i.X == mx){
			ans[ind[i.Y]] = 0;
		}
		else{
			ans[ind[i.Y]] = 1;
		}
	}
	if(common == mx){
		ans[index] = 0;
	}
	else{
		ans[index] = 1;
	}
}

void solve(int v , int l , int r , int cnt){
	if(cnt == 0){
		return;
	}
	if(r - l == 1){
		ans[back_edge[v][l].Y] = 1;
		return;
	}
	int mid = l + r >> 1;
	int L = query_back_edge(back_edge[v] , l , mid) , R = cnt - L;
	solve(v , l , mid , L);
	solve(v , mid , r , R);
}

int cmp(pii x , pii y){
	return H[x.X] > H[y.X];
}

vector<int> find_roads(int N, vector<int> U, vector<int> V) {
	fill(ans , ans + MAXN * MAXN, -1);
	n = N; m = SZ(U);
	for(int i = 0 ; i < m ; i++){
		adj[V[i]].push_back({U[i] , i});
		adj[U[i]].push_back({V[i] , i});
		E.push_back({V[i] , U[i]});
	}
	DFS(0);
	common = query(tree);
	for(int i = 0 ; i < m ; i++){
		if(H[E[i].X] < H[E[i].Y]){
			swap(E[i].X , E[i].Y);
		}
	}
	for(int i = 0 ; i < m ; i++){
		if(tree[i] == 0){
			Calc(E[i].X , E[i].Y , i);
		}
	}
	for(int i = 0 ; i < n ; i++){
		back_edge[i].push_back({i , 0});
	}
	for(int i = 0 ; i < m ; i++){
		if(tree[i] == 1 && ans[i] == -1){
			ans[i] = 1;
		}
		if(ans[i] == -1){
			back_edge[E[i].X].push_back({E[i].Y , i});
		}
	}
	for(int i = 0 ; i < n ; i++){
		sort(back_edge[i].begin() , back_edge[i].end() , cmp);
		int cnt = query_back_edge(back_edge[i] , 1 , SZ(back_edge[i]));
		solve(i , 1 , SZ(back_edge[i]) , cnt);
	}
	vector<int> res;
	for(int i = 0 ; i < m ; i++){
		if(ans[i] == -1){
			ans[i] = 0;
		}
		if(ans[i]){
			res.push_back(i);
		}
	}
	return res;
}

컴파일 시 표준 에러 (stderr) 메시지

simurgh.cpp: In function 'void solve(int, int, int, int)':
simurgh.cpp:128:14: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
  128 |  int mid = l + r >> 1;
      |            ~~^~~

• Subtask 1: 13 / 13
• Subtask 2: 17 / 17
• Subtask 3: 21 / 21
• Subtask 4: 19 / 19
• Subtask 5: 30 / 30