directed acyclic graph (shortest path)

#include<iostream>
#include<vector>
#include<list>
using namespace std;
// taking graph
int arr[5][5]={{0,10,0,5,0},{0,0,1,2,0},{0,0,0,0,4},{0,3,9,0,2},{7,0,6,0,0}};
list<int> r;
int time=0;
void dfs(int i,int stime[],int ftime[],int parent[],int color[]);
int main()
{
    int v;
    cout<<"enter number of vertices\n";
    cin>>v;
    int stime[v],ftime[v],parent[v],color[v];
    int i,j;
    int key[v];
    // taking three arrays color ,parent,key
    for(i=0;i<v;i++)
    {
        key[i]=INT_MAX;
    }
    // key denotes shortest path from source vertex
    key[0]=0;
    //  denoting color to denote status of anode
    for(i=0;i<v;i++)
    {
        color[i]=0;
        parent[i]=-1;
    }
    // parent denotes the parent of a node
    for(i=0;i<v;i++)
    {
        if(color[i]==0)
        {
                 dfs(i,stime,ftime,parent,color);
        }

    }

    list<int>::iterator it;
    for(it=r.begin();it!=r.end();it++)
    {
        for(i=0;i<v;i++)
        {
            if(arr[*it][i]!=0)
            {
                if(key[i]>key[*it]+arr[*it][i])
                {
                    key[i]=key[*it]+arr[*it][i];
                }
            }
        }
    }
    // printing shortest path
    for(i=1;i<v;i++)
    {
        cout<<key[i]<<endl;
    }
}
// implementing depth first search
void dfs(int i,int stime[],int ftime[],int parent[],int color[])
{
    time++;
    color[i]=1;
    stime[i]=time;
    int j;
    for(j=0;j<5;j++)
    {
        if(arr[i][j]!=0 && color[j]==0)
        {
            dfs(j,stime,ftime,parent,color);
        }
    }
     time++;
    ftime[i]=time;
    color[i]=2;
    r.push_front(i);
}