Floating Point Exception in C++

Question

I am getting a floating point exception in my code but unable to sort it out. I dnt know what the problem is. Not so good at C++ program and just going through the formulas given. Please help me:

Program:

#include<iostream.h>
#include<conio.h>
#include <stdlib.h>

void main()
{
    clrscr();
    int a,b,c,d,ctr,j,Q=1,K=1 ;
    float q0=0.7, p = 0.5 ;
    int phe[3][3];
    double dist[3][3] , mem[3][3],exp[3][3],eplt[3][3], rnd;
    cout<<"enter the iterations, cities , ants ";
    cin>>a>>b>>c;
    for (int i=0;i<3;i++)
    {
        for (j=0;j<3;j++)
        {
            dist[i][j]=(double)rand()/(double)RAND_MAX;
            if (i==j)
            dist[i][j]=0;
        }
    }
    for (i=0;i<3;i++)
    {
        for (j=0;j<3;j++)
        {
            cout<< dist[i][j]<<"\t";
        }
        cout<<"\n";
    }

    cout<<"pheromone matrix "<<endl;
    for (i=0;i<3;i++)
    {
        for (j=0;j<3;j++)
        {
            if (i==j)
                phe[i][j]=0;
            else
                phe[i][j]=1;
        }
    }

    for ( i=0;i<3;i++)
    {
        for ( j=0;j<3;j++)
        {
            cout<< phe[i][j]<<"\t";
        }
        cout<<"\n";
    }

    cout<< "after iteration "<<endl;
    for (i=0;i<3;i++)
    {
        ctr=0;
        for (int k=0;k<3;k++)
        {
            // mem[i][k]=(rand()%b)+1;
            // cout<<"memory"<<mem[i][k]<<"\n";
            rnd= (double)rand()/(double)RAND_MAX;
            cout<<"hhhhhhh"<<rnd;
            if (rnd<=q0)
            {
                cout<<"Exploitation\n";
                eplt[i][ctr] =(p*phe[i][k])+(Q/K);  
            }
            else
            {
                cout<<"EXPLORATION\n";
                eplt[i][ctr]= phe[i][k]/dist[i][k];
            }
            ctr++;
        }
    }
    for (i=0;i<3;i++)
    {
        for (int k=0;k<3;k++)
        {
            cout <<eplt[i][k]<<"\t";
        }
        cout<<"\n";
    }
    getch();
}

I am getting the error after first loop after "after iteration" completes. This is the output:

enter the iterations, cities , ants 3 4 4

0 0.003967 0.335154 0.033265 0 0.2172 0.536973 0.195776 0

pheromone matrix 0 1 1 1 0 1 1 1 0

after iteration hhhhhhh0.949919EXPLORATION Floating point error: Domain. Abnormal program termination

Answer 1

I think this line (right after cout<<"EXPLORATION\n";:

eplt[i][ctr]= phe[i][k]/dist[i][k];

is the problem. When i == k, then dist[i][k] == 0.0.

Answer 2

At first glance: are you calling the line

eplt[i][ctr]= phe[i][k]/dist[i][k];

with i = 0 and k = 0 ? From the initialization, dist[0][0] = 0, and you would have a division by zero exception.