C++ - DFS code error - c++

Question

I tried to implement this algorithm but there's some logical error. The algorithm is given below.
DFS(G)
1. for each vertex u ∈ G.V
2. u.color = WHITE
3. u.pi = NIL
4. time = 0
5. for each vertex u ∈ G.V
6. if u.color == WHITE
7. DFS-VISIT(G,u)
DFS-VISIT(G,u)
1. time = time + 1
2. u.d = time
3. u.color = GRAY
4. for each v ∈ G.Adj[u]
5. if v.color == WHITE
6. v.pi = u
7. DFS-VISIT(G,v)
8. u.color = BLACK
9. time = time + 1
10. u.f = time
Code:
#include <bits/stdc++.h>
using namespace std;
#define WHITE 0
#define GRAY 1
#define BLACK 2
#define SIZE 100
int Time;
int adj[SIZE][SIZE];
int color[SIZE];
int parent[SIZE];
int d[SIZE];
void dfs_Visit(int G, int u)
{
Time++;
d[u] = Time;
color[u] = GRAY;
for(int i = 0; i < G; i++)
{
if(color[i] == WHITE)
{
parent[i] = u;
dfs_Visit(G, i);
}
}
color[u] = BLACK;
Time++;
cout << u << " ";
}
void dfs(int G)
{
for(int i = 0; i < G; i++)
{
color[i] = WHITE;
parent[i]=NULL;
}
Time=0;
cout << "DFS is ";
for(int i = 0; i < G; i++)
{
if(color[i] == WHITE)
{
dfs_Visit(G, i);
}
}
}
int main()
{
int vertex;
int edge;
cout << "VERTEX & Edge : ";
cin >> vertex >> edge;
cout << "Vertex is : " << vertex <<endl;
cout << "Edge is : " << edge <<endl;
int node1, node2;
for(int i = 0; i < edge; i++)
{
cout << "EDGE " << i << ": ";
cin >> node1 >> node2;
adj[node1][node2] = 1;
adj[node2][node1] = 1;
}
dfs(vertex);
}
Output picture
Inputs:
VERTEX & Edge : 4 5
Vertex is : 4
Edge is : 5
EDGE 0: 0 1
EDGE 1: 1 2
EDGE 2: 2 0
EDGE 3: 0 3
EDGE 4: 2 4
Output:
DFS is 3 2 1 0
And the accepted result is 2 1 3 0

Answer 1

The problem is that you haven't coded DFS-VISIT step 4 correctly
Step 4 says for each v ∈ G.Adj[u] but your code says for(int i=0; i<G; i++). Those aren't the same thing at all. You should only visit the adjacent vertexes.
In fact if you look at your code you never use adj at all. That can't be right.