Исходный код
#include <iostream>
#include <vector>
#include <fstream>
#include <set>
#include <queue>
#include <algorithm>
#include <map>
#include <string>
#include <cstring>

using namespace std;

queue <int> q;

bool mas[4000][4000];
bool used[4000];

map<int, string> f;
map<string, int> of;

vector<pair<string, string>> inVertex;

vector <string> s;

int n, v2, v1, i, j;

void bfs(int v1) {
	cout << f.find(v1)->second << endl;
	q.push(v1);
	used[v1] = true;
	while(!q.empty())
	{
		int v = q.front();
		q.pop();
		for(int i = 1; i < s.size() + 1; ++i)
			if(!used[i] && mas[v][i])
			{
				used[i] = true;
				q.push(i);
				cout << f.find(i)->second << endl;
			}
	}
}

void dfs(int v1) {
used[v1] = true;
cout << f.find(v1)->second << endl;
for(int i = 1; i <= s.size(); i++)
if(mas[v1][i] && !used[i]) {
	dfs(i);
	}
}


int main() {
char graph_type, search_type;
string start;
//ifstream in;
//in.open("C:\\Users\\DNSPC\\Desktop\\input.txt");
cin >> graph_type >> start >> search_type;
string v1, v2;
while (cin>>v1) {
		cin >> v2;
		inVertex.push_back(make_pair(v1,v2));
		if (find(s.begin(), s.end(), v1) == s.end()) s.push_back(v1);
		if (find(s.begin(), s.end(), v2) == s.end()) s.push_back(v2);
	}

sort(s.begin(), s.end());

for (i = 1; i <= s.size(); i++) {
	f.insert(make_pair(i, s[i - 1]));
	of.insert(make_pair(s[i - 1], i));
}
for (i = 0; i < inVertex.size(); i++) {
int ind1, ind2;
ind1 = of.find(inVertex[i].first)->second;
ind2 = of.find(inVertex[i].second)->second;
		mas[ind1][ind2] = 1;
		if (graph_type == 'u') {
		mas[ind2][ind1] = 1;
		}
}

	if (search_type == 'd')
dfs(of.find(start)->second);
	else bfs(of.find(start)->second);

//in.close();

system("pause");

return 0;
}