C++ Programming Code Examples
C++ > Computer Graphics Code Examples
Program for Topological Sorting in Graphs
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/* Program for Topological Sorting in Graphs
This C++ program, using an adjacency matrix, displays the times at which the different times at which nodes are visited and left thereby producing a linear ordering of vertices in a graph.
A graph is a set of nodes connected by edges. */
#include <iostream>
#include <conio.h>
using namespace std;
struct node_info
{
int no;
int lv_time, st_time;
}*q = NULL, *r = NULL;
struct node
{
node_info *pt;
node *next;
}*top = NULL, *p = NULL, *np = NULL;
int c = 0;
void push(node_info *ptr)
{
np = new node;
np->pt = ptr;
np->next = NULL;
if (top == NULL)
{
top = np;
}
else
{
np->next = top;
top = np;
}
}
node_info *pop()
{
if (top == NULL)
{
cout<<"underflow\n";
}
else
{
p = top;
top = top->next;
return(p->pt);
delete(p);
}
}
void topo(int *v,int am[][7],int i)
{
q = new node_info;
q->no = i;
q->st_time = c;
cout<<"start time for node no "<<q->no<<":"<<c<<endl;
push(q);
v[i] = 1;
for (int j = 0; j < 7; j++)
{
if (am[i][j] == 0 || (am[i][j] == 1 && v[j] == 1))
continue;
else if(am[i][j] == 1 && v[j] == 0)
{
c++;
topo(v,am,j);
}
}
c++;
r = pop();
cout<<"leave time for "<<r->no<<":"<<c<<endl;
return;
}
int main()
{
int v[7],am[7][7];
for (int i = 0; i < 7; i++)
v[i] = 0;
for (int i = 0; i < 7; i++)
{
cout<<"enter the values for adjacency matrix row:"<<i + 1<<endl;
for(int j = 0; j < 7; j++)
{
cin>>am[i][j];
}
}
topo(v,am,0);
getch();
}
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