Submission #407399

#	Time	Username	Problem	Language	Result	Execution time	Memory
407399		peuch	Simurgh (IOI17_simurgh)	C++11	30 / 100	3066 ms	5000 KiB

simurgh

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

const int MAXN = 1010;

int n, m;
vector<int> u, v;

vector<int> ar[MAXN], id[MAXN];
int marc[MAXN];
int grp[200000];
int cnt[200000];

int rep[MAXN], tam[MAXN];

vector<int> getPath(int cur, int fim, int x);
vector<int> getST(vector<int> base);
bool uni(int a, int b);
int find(int a);

vector<int> find_roads(int _n, vector<int> _u, vector<int> _v) {
	n = _n;
	u = _u, v = _v;
	m = u.size();
	
	for(int i = 0; i < u.size(); i++){
		ar[u[i]].push_back(v[i]);
		id[u[i]].push_back(i);
		ar[v[i]].push_back(u[i]);
		id[v[i]].push_back(i);
	}
	
	for(int i = 0; i < u.size(); i++){
		if(grp[i] != 0) continue;
//		printf("Calculating: %d\n", i);
		
		for(int j = 0; j < n; j++) marc[j] = 0;
		vector<int> path = getPath(u[i], v[i], i);
		
		
		if(path.empty()) {
//			printf("\tBridge\n");
			grp[i] = 1;
			continue;
		}
		
//		printf("\tCycle: %d ", i);
//		for(int j = 0; j < path.size(); j++)
//			printf("%d ", path[j]);
//		printf("\n");
		
		vector<int> r = getST(path);
		path.push_back(i);
		
		int maxi = 0;
		bool flag = false;
		for(int j = 0; j < path.size(); j++){
			if(grp[path[j]] != 0){
				if(flag) continue;
				if(grp[path[j]] == 1) continue;
				flag = true;
			}
			
			vector<int> test = r;
			for(int k = 0; k < path.size(); k++)
				if(k != j) test.push_back(path[k]);
			
			cnt[j] = count_common_roads(test);
			maxi = max(maxi, cnt[j]);
			
//			printf("Tested: %d -> %d\n", path[j], cnt[j]);
		}	
		for(int j = 0; j < path.size(); j++){
			if(grp[path[j]] != 0) continue;
			if(cnt[j] == maxi) grp[path[j]] = -1;
			if(cnt[j] != maxi) grp[path[j]] = 1;
		}
	}
	vector<int> ans;
	for(int i = 0; i < m; i++)
		if(grp[i] == 1) ans.push_back(i);
	
//	for(int i = 0; i < ans.size(); i++){
//		printf("%d ", ans[i]);
//	}
//	printf("\n");
	
	return ans;
}

vector<int> getPath(int cur, int fim, int x){
	marc[cur] = 1;
	vector<int> ret;
	for(int i = 0; i < ar[cur].size(); i++){
		int viz = ar[cur][i];
		if(marc[viz]) continue;
		if(id[cur][i] == x) continue;
		ret = getPath(viz, fim, x);
		if(ret.empty() && viz != fim) continue;
		ret.push_back(id[cur][i]);
		return ret;
	}
	return ret;
}

vector<int> getST(vector<int> base){
	vector<int> ret;
	for(int i = 0; i < n; i++){
		tam[i] = 1;
		rep[i] = i;
	}
	for(int i = 0; i < base.size(); i++)
		uni(u[base[i]], v[base[i]]);
	for(int i = 0; i < m; i++)
		if(uni(u[i], v[i])) ret.push_back(i);
	return ret;
}

bool uni(int a, int b){
	a = find(a);
	b = find(b);
	if(a == b) return 0;
	if(tam[a] < tam[b]) swap(a, b);
	tam[a] += tam[b];
	rep[b] = a;
	return 1;
}

int find(int a){
	if(a == rep[a]) return a;
	return rep[a] = find(rep[a]);
}
/*
5 7
0 1
1 2
2 3
3 4
0 2
1 3
4 2
1 3 4 6
*/

Compilation message (stderr)

simurgh.cpp: In function 'std::vector<int> find_roads(int, std::vector<int>, std::vector<int>)':
simurgh.cpp:27:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   27 |  for(int i = 0; i < u.size(); i++){
      |                 ~~^~~~~~~~~~
simurgh.cpp:34:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   34 |  for(int i = 0; i < u.size(); i++){
      |                 ~~^~~~~~~~~~
simurgh.cpp:58:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   58 |   for(int j = 0; j < path.size(); j++){
      |                  ~~^~~~~~~~~~~~~
simurgh.cpp:66:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   66 |    for(int k = 0; k < path.size(); k++)
      |                   ~~^~~~~~~~~~~~~
simurgh.cpp:74:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   74 |   for(int j = 0; j < path.size(); j++){
      |                  ~~^~~~~~~~~~~~~
simurgh.cpp: In function 'std::vector<int> getPath(int, int, int)':
simurgh.cpp:95:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   95 |  for(int i = 0; i < ar[cur].size(); i++){
      |                 ~~^~~~~~~~~~~~~~~~
simurgh.cpp: In function 'std::vector<int> getST(std::vector<int>)':
simurgh.cpp:113:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  113 |  for(int i = 0; i < base.size(); i++)
      |                 ~~^~~~~~~~~~~~~

• Subtask 1: 13 / 13
• Subtask 2: 17 / 17
• Subtask 3: 0 / 21
• Subtask 4: 0 / 19
• Subtask 5: 0 / 30