Floyed-Warshall (OWN)

//note : do not use INT_MAX for comparison,use a big number (i.e. : 999999) instead
#include<iostream>
using namespace std;

int vertex,edge,source;
int adjacency_matrix[100][100],weight_matrix[100][100],parent_matrix[100][100];
int weight_matrix_1[100][100][100],parent_matrix_1[100][100][100];
int parent[100],cost[100],visited[100];

void inputGraph();
int findMinimum(int,int);
void initializeMatrix();
void showMatrix();
void output();

int main(void)
{
    inputGraph();
    initializeMatrix();
    showMatrix();
    output();
    return 0;
}
void inputGraph()
{
    cout<<"Total vertex : ";
    cin>>vertex;
    cout<<"Total edge   : ";
    cin>>edge;
    int i,j;
    //make all weight infinity
    for(i=1; i<=vertex; i++)
    {
        for(j=1; j<=vertex; j++)
        {
            weight_matrix[i][j]=999999;
            parent_matrix[i][j]=0;
            if(i==j)
            {
                weight_matrix[i][j]=0;
            }
        }
    }
    // scan adjacency matrix and weight
    for(i=1; i<=edge; i++)
    {
        int start,finish;
        cout<<"Enter start and end node for edge "<<i<<" : ";
        cin>>start;
        cin>>finish;
        adjacency_matrix[start][finish]=1;
        parent_matrix[start][finish]=start;
        cout<<"Enter weight for edge "<<i<<" : ";
        cin>>weight_matrix[start][finish];
    }
    cout<<endl<<"The adjacency matrix is : "<<endl<<endl;
    for(i=1; i<=vertex; i++)
    {
        for(j=1; j<=vertex; j++)
        {
            cout<<adjacency_matrix[i][j]<<" \t\t";
        }
        cout<<endl;
    }
    cout<<endl;
    cout<<"The weight matrix is : "<<endl<<endl;
    for(i=1; i<=vertex; i++)
    {
        for(j=1; j<=vertex; j++)
        {
            cout<<weight_matrix[i][j]<<" \t\t";
        }
        cout<<endl;
    }
    cout<<endl;
    cout<<"The parent matrix is : "<<endl<<endl;
    for(i=1; i<=vertex; i++)
    {
        for(j=1; j<=vertex; j++)
        {
            cout<<parent_matrix[i][j]<<" \t\t";
        }
        cout<<endl;
    }
    cout<<endl;
}
int findMinimum(int a,int b)
{
    if(a<b)
    {
        return a;
    }
    return b;
}
void initializeMatrix()
{
    int i,j,k;
    //take input
    for(k=0; k<=vertex; k++)
    {
        for(i=1; i<=vertex; i++)
        {
            for(j=1; j<=vertex; j++)
            {
                //calculate distance-dij
                if(k==0)
                {
                    weight_matrix_1[k][i][j]=weight_matrix[i][j];
                }
                else
                {
                    weight_matrix_1[k][i][j]=findMinimum(weight_matrix_1[k-1][i][j],(weight_matrix_1[k-1][i][k]+weight_matrix_1[k-1][k][j]));
                }
                //calculate parent-Pij
                if(k==0)
                {
                    parent_matrix_1[k][i][j]=parent_matrix[i][j];
                }
                else
                {
                    if(weight_matrix_1[k-1][i][j]<=(weight_matrix_1[k-1][i][k]+weight_matrix_1[k-1][k][j]))
                    {
                        parent_matrix_1[k][i][j]=parent_matrix_1[k-1][i][j];
                    }
                    else if(weight_matrix_1[k-1][i][j]>(weight_matrix_1[k-1][i][k]+weight_matrix_1[k-1][k][j]))
                    {
                        parent_matrix_1[k][i][j]=parent_matrix_1[k-1][k][j];
                    }
                }
            }
        }
    }
}
void showMatrix()
{
    int i,j,k;
    //show output
    for(k=0; k<=vertex; k++)
    {
        //print weight
        cout<<"Dij K["<<k<<"] : "<<endl<<endl;
        for(i=1; i<=vertex; i++)
        {
            for(j=1; j<=vertex; j++)
            {
                cout<<weight_matrix_1[k][i][j]<<" \t\t";
            }
            cout<<endl;
        }
        cout<<endl;
        //print parent
        cout<<"Pij K["<<k<<"] : "<<endl<<endl;
        for(i=1; i<=vertex; i++)
        {
            for(j=1; j<=vertex; j++)
            {
                cout<<parent_matrix_1[k][i][j]<<" \t\t";
            }
            cout<<endl;
        }
        cout<<endl;
        cout<<endl;
    }
}
void output()
{
    int i,j,k=vertex,sum;
    for(i=1; i<=vertex; i++)
    {
        cout<<endl<<"For node "<<i<<" : "<<endl<<endl;
        sum=0;
        for(j=1; j<=vertex; j++)
        {
            if(parent_matrix_1[k][i][j]==0)
            {
                cout<<"Shortest distance from "<<i<<" to "<<j<<" is : "<<weight_matrix_1[vertex][i][j]<<" \t\tParent : NIL"<<endl;
            }
            else
            {
                cout<<"Shortest distance from "<<i<<" to "<<j<<" is : "<<weight_matrix_1[vertex][i][j]<<" \t\tParent : "<<parent_matrix_1[k][i][j]<<endl;
            }
            sum = sum + weight_matrix_1[k][i][j];
        }
        cout<<"Shortest distance for visiting all nodes from node "<<i<<" is : "<<sum<<endl;
    }
}
/*
input:
5
9
1 2
3
3 2
4
4 3
-5
5 4
6
1 5
-4
1 3
8
4 1
2
2 5
7
2 4
1
*/