Algorithm, c++, BFS와 DFS 구현

#include <iostream>
#include <queue>
#include <stack>
 
using namespace std;
 
int number = 7;
bool c[7];
vector<int> a[8];
 
void bfs(int start) {
    queue<int> q;
    q.push(start);
    c[start] = true;
    while (!q.empty()) {
        int x = q.front();
        q.pop();
        cout << x << ' ';
        for (int i = 0; i < a[x].size(); i++) {
            int y = a[x][i];
            if (!c[y]) {
                q.push(y);
                c[y] = true;
            }
        }
    }
}
 
void dfs(int start) {
    if (c[start]) return;
    c[start] = true;
    cout << start << ' ';
    for (int i = 0; i < a[start].size(); i++) {
        int y = a[start][i];
        dfs(y);
    }
}
 
void linkEdge(int x, int y) {
    a[x].push_back(y);
    a[y].push_back(x);
}
 
int main() {
    linkEdge(1, 2);
    linkEdge(1, 3);
    linkEdge(2, 3);
    linkEdge(2, 4);
    linkEdge(2, 5);
    linkEdge(4, 5);
    linkEdge(3, 6);
    linkEdge(3, 7);
    linkEdge(6, 7);
 
 
    dfs(1);
 
    return 0;
}