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conv-ldb/generate.C

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/* Generate a random graph, given the number of nodes, the number of
   connections per node.

dump graph if "tofile" is true
Output form: directory graphN/ containing files graph0 ... graphN-1
             file graphK has C, the number of connections, followed by
             a list of C vertices that K is connected to

Modified from the original: changed output format, and converted main to a parametered function
*/
#include <stdio.h>
#include <stdlib.h>

/* comment this out to test and change CmiPrintf to printf */
#include "converse.h"
#include "graphdefs.h"

void addEdge(VerticesListType *graph, EdgeListType *l,int fm,int to);
void addspEdge(VerticesListType *graph, EdgeListType *, int, int);
int edgeExists(VerticesListType *graph, int fm, int to);
static Q * makeQueue(void);
static int isEmpty(Q*);
static int dequeue(Q*);

#define VMAX 2050
int V; /* no. of vertices */
int E; /* no. of edges */
int C; /* no. of connections per vertex */

VerticesListType * InitVertices(EdgeListType * EdgeList, int V, int E);


extern "C" void gengraph(int, int, int, int *, int *, int);

/* For testing... 
int main(int argc, char **argv)
{
  gengraph(atoi(argv[1]), atoi(argv[2]), atoi(argv[3]));
}
*/

static void printOut(VerticesListType *vertices);
static void copyOut(VerticesListType *vertices, int *npe, int *pes);
static void initGraph(VerticesListType *graph);
static void diameter(VerticesListType *graph);
static void AddEdges(VerticesListType *graph, EdgeListType *EdgeList, int V, int n);

void gengraph(int pV, int pC, int pseed, int *pes, int *npe, int tofile)
{ int i;
  VerticesListType graph;
  int seed;
  EdgeListType * EdgeList;
  /* VerticesListType * vertices; */
  extern EdgeListType * InitEdgeList(int);
  char dircmd[20], dirname[10];

  V = pV;
  C = pC;
  seed = pseed;
  
  if (CmiMyPe() == 0)
  CmiPrintf("for %d PEs, connectivity %d... \n", V, C);

  /* make a directory */
  if (tofile && CmiMyPe() == 0) {
  sprintf(dirname, "graph%d", V);
  sprintf(dircmd, "mkdir %s", dirname);
  if (system(dircmd) == -1) {
    CmiAbort("CLD> call to system() failed!");
  }
  }
  
  /* for (i=0; i<seed; i++) rand(); */
  for (i=0; i<seed; i++) CrnRand();
  if ((V*C %2) != 0) printf("V*C must be even\n");
  E = V*C/2;
  initGraph(&graph);
  EdgeList = InitEdgeList(E);
  AddEdges(&graph, EdgeList, V, E); 
  /*  vertices = (VerticesListType *) InitVertices(EdgeList, V,E); */

  if (tofile) {
    if (CmiMyPe()==0) printOut(&graph);
  }
  else copyOut(&graph, npe, pes);

  if (CmiMyPe()==0) diameter(&graph);
}

#if 0
static void AddEdges(EdgeListType *EdgeList, int V, int n)
   /* Add more edges to make up a total of E edges */
{int i,j,w,x,y;
/* first add edges for a C-way spanning tree.*/
int c1;
if (C>1) c1 = C-1;

for (i=0; i< V/c1; i++)
  for (j=0; j<c1; j++) {
      w = c1*i + j +1; 
      /* printf("considering (%d, %d)\n", i, w);  */
      if (w < V) {
    addEdge(EdgeList,i,w);
    /* printf(" --- added.\n"); */
      }
      else /*printf(" not added.\n")*/; 
  }
n -= (V-1);

 for (i=0; i<n; i++) 
   {
     do {
       do {
     x = CrnRand() % V;
       } while (connections(x) >= C);
       do {
     y = CrnRand() % V;
       } while ((y== x) || connections(y) >= C);
     } while (edgeExists(x,y));
     addEdge(EdgeList, x, y);
   }
}
#endif

static void AddEdges(VerticesListType *graph, EdgeListType *EdgeList, int V, int n)
    /* Add more edges to make up a total of E edges */
  { int i,j,w,x,y,k;
    int c1,max,maxi;
    int **varr;
    int varrlen,count=0;
    int flag=0;

    /* first add edges for a C-way spanning tree.*/
        varr=(int **)calloc(V, sizeof(int*));
        for (i=0;i<V;i++)
            varr[i] = (int *)calloc(2, sizeof(int));
    
  c1 = 1;
    if (C>1) c1 = C-1;

    for (i=0; i<= V/c1; i++)
      for (j=0; j<c1; j++) {
          w = c1*i + j +1; 
          if (w < V) {
        addEdge(graph, EdgeList,i,w);
        count++;
                  }
              }
    
    /*varr is array of vertices and free connection for each vertex*/
    j=0;
    for (i=0;i<V;i++)
        if(connections(graph, i)<C)
        {
         varr[j][0]=i;
         varr[j][1]=C-connections(graph,i);
         j++;
        }
    varrlen=j;
    CmiAssert(varrlen>0);
    
    /*for all edges except last 10 , edge is formed by randomly selecting vertices from varr*/

    n -= count;

    /*if (n>10)
    for (j=0; j<n-10; j++) 
       {
            flag=0;
        do {
             x = rand() % varrlen;
             do {
                 y = rand() % varrlen;
                } while (y == x) ;
            }while (edgeExists(varr[x][0],varr[y][0]));
         addEdge(EdgeList, varr[x][0], varr[y][0]);
             
             varr[x][1]=varr[x][1]-1;
         varr[y][1]=varr[y][1]-1;

         //If no free connections left for a vertex remove it from varr     

         if (varr[x][1]==0) {
                 flag=1;
                 for (i=x;i<varrlen-1;i++)
                    {   
                     varr[i][0]=varr[i+1][0];
                     varr[i][1]=varr[i+1][1];
                    }
                 varrlen--;
                }
         if ((y>x)&&(flag)) {
                         
                    if (varr[y-1][1]==0)   
                            {
                              for (i=y-1;i<varrlen-1;i++)
                                {   
                                 varr[i][0]=varr[i+1][0];
                                 varr[i][1]=varr[i+1][1];
                                }
                              varrlen--;
                            }
                }                   
             else if (varr[y][1]==0) {
                 for (i=y;i<varrlen-1;i++)
                    {   
                     varr[i][0]=varr[i+1][0];
                     varr[i][1]=varr[i+1][1];
                    }
                 varrlen--;
                }
       }

    //for last 10 edges, first vertex is one with max free connections and other vertex is randomly chosen 

    if (n>10) k=10; else k = n;*/

    k=n;
    for (j=0;j<k;j++)
        {
                flag=0;
                max=0;
                maxi=0;
                for (i=0;i<varrlen;i++)
                    if (varr[i][1]>max) { max=varr[i][1];maxi=i;}
                x = maxi;
                do {
                     y = rand() % varrlen;
                   } while (y == x) ;

                /*if (edgeExists(varr[x][0],varr[y][0])) 
                    if (j==k-1) addspEdge(EdgeList,varr[x][0],varr[y][0]);
                        else do {
                                y = rand() % varrlen;
                             } while (y == x);
                else addEdge(EdgeList,varr[x][0],varr[y][0]); */

                if (edgeExists(graph, varr[x][0],varr[y][0])&&(j==k-1))
                    addspEdge(graph, EdgeList,varr[x][0],varr[y][0]);
                else    
                {
                    while((y==x)||(edgeExists(graph,varr[x][0],varr[y][0])))
                            y = rand() % varrlen;
                    addEdge(graph,EdgeList,varr[x][0],varr[y][0]); 
                }

                varr[x][1]=varr[x][1]-1;
                    varr[y][1]=varr[y][1]-1;
                        
                if (varr[x][1]==0) 
                    {
                     flag=1;
                     for (i=x;i<varrlen-1;i++)
                        {   
                         varr[i][0]=varr[i+1][0];
                         varr[i][1]=varr[i+1][1];
                        }
                     varrlen--;
                    }   
                if ((y>x)&&(flag))         
                    {
                         if (varr[y-1][1]==0)   
                            {
                              for (i=y-1;i<varrlen-1;i++)
                                {   
                                 varr[i][0]=varr[i+1][0];
                                 varr[i][1]=varr[i+1][1];
                                }
                              varrlen--;
                            }
                    }                   
                        else if (varr[y][1]==0)
                    {
                         for (i=y;i<varrlen-1;i++)
                            {   
                             varr[i][0]=varr[i+1][0];
                             varr[i][1]=varr[i+1][1];
                            }
                         varrlen--;
                    }
            }         
        for (i=0;i<V;i++) free(varr[i]);
        free(varr);
}


void fillAdjArray(Edge *edges, VerticesListType *vlist, int V, int E);
void sortAdjArrays(VerticesListType *vlist);
static void sort(int *adj, int fromIndex, int toIndex);
void countDegrees(Edge *edges, Vertex *vertRecs, int V, int E);

VerticesListType * 
InitVertices(EdgeListType * EdgeList, int V, int E)
{ /* returns a structure of type VerticesListType, which contains an arry of 
     vertex records, and an array of adjacency information. See typedef. */
  /* First allocate the adjacency subarray of size E, and vertex subarray size V.
     Then count the occurences of each vertex in the Edgelist in vertex.degree.
     Then compute the real adjListInd = sum from 0 to i-1 of the previous degrees.
     Then, traverse edge list, and enter each edge in two adj lists.
     Then sort individual adj-lists, separately. */
  VerticesListType * vlist;

  vlist = (VerticesListType *) malloc(sizeof(VerticesListType));
  _MEMCHECK(vlist);
  vlist->numVertices = V;
  vlist->vertexArray = (Vertex *) malloc(V*sizeof(Vertex));
  _MEMCHECK(vlist->vertexArray);
  vlist->adjArray = (int *) malloc(2*E*sizeof(int)); 
                    /* as each edge is entered twice */
  _MEMCHECK(vlist->adjArray);
  countDegrees(EdgeList->edges, vlist->vertexArray, V, E);
  fillAdjArray(EdgeList->edges, vlist, V, E);
  sortAdjArrays(vlist);
  return(vlist);
}

void countDegrees(Edge *edges, Vertex *vertRecs, int V, int E)
{ /* initialize the degrees of all vertices to 0. 
     Traverse the edge list, incrementing the degree of the 2 nodes for each edge.
     */
 int i, count;
 
 for (i=0; i<V; i++)
   { vertRecs[i].degree = 0;
     vertRecs[i].next = 0;}
 for (i=0; i<E; i++)
   {vertRecs[ edges[i].node1 ].degree++;
    vertRecs[ edges[i].node2 ].degree++;}

/* now fill adjListInd, by starting a counter at 0, and adding degrees of visited
   nodes. */
 count = 0;
 for (i=0; i<V; i++)
   { vertRecs[i].adjListInd = count;
     count += vertRecs[i].degree;
   }
}

void fillAdjArray(Edge *edges, VerticesListType *vlist, int V, int E)
{ /* Insert each edge <x,y> as an entry y in x's adj list, and vice versa. */
  int i, x,y;
 int * adj;
 Vertex * vertexRecs;

 adj = vlist->adjArray;
 vertexRecs = vlist->vertexArray;

  for (i=0; i<E; i++)
    { x = edges[i].node1; y = edges[i].node2;
      adj[ vertexRecs[x].adjListInd + vertexRecs[x].next ] = y;
      vertexRecs[x].next++;
      adj[ vertexRecs[y].adjListInd + vertexRecs[y].next ] = x;
      vertexRecs[y].next++;
    }
}

void sortAdjArrays(VerticesListType *vlist)
{ /* sort each section of the array corresponding to each vertex. */
  int V, i;
  int dupcount;

  V = vlist->numVertices;
  for (i=0; i<V; i++)
    { sort(vlist->adjArray, 
       vlist->vertexArray[i].adjListInd,
       vlist->vertexArray[i].adjListInd + vlist->vertexArray[i].degree -1);
    }
  /* eliminate duplicates. May be should be merged with above? */
  dupcount = 0;
  for (i=0; i<V; i++)
    { int m,n, limit;
      int * adj;

      m = vlist->vertexArray[i].adjListInd;
      n = m+1;
      limit = m + vlist->vertexArray[i].degree; /* this is the first index
                           not belonging to this vertex.*/
      adj = vlist->adjArray;
      /* do this in 2 phases. First phase: m and n are exactly one away.
     goes on until the first duplicate is found. In this phase, there
     is no need to assign values (no shifting is going on.) */
      while ((adj[m] != adj[n]) && (n < limit)) {m++; n++;}
      /* Phase 2: */
      while (n<limit) {
    while ((adj[m] == adj[n]) && (n<limit)) 
      { n++; dupcount++; vlist->vertexArray[i].degree--;}
    adj[m+1] = adj[n]; /*move the non duplicate back to its new position*/
    m++; n++;
      }
    }
/* printf("number of duplicate edges removed = %d\n", dupcount/2);*/
/* Here is an assignment to a global variable.... */
if ((dupcount % 2) != 0) {printf("error. duplicates not even.\n"); }
E -= dupcount/2;
}

static void sort(int *adj, int fromIndex, int toIndex)
{ int i,j, tmp;
  short changed;
  changed = 1;
  for (i=toIndex; ((i>fromIndex) && changed); i--)
    { changed = 0;
      for (j=fromIndex; j<i; j++)
    { if (adj[j] > adj[j+1])
        { /* swap */
          changed = 1;
          tmp = adj[j];
          adj[j] = adj[j+1];
          adj[j+1] = tmp;
        }
    }
    }
}

static void copyOut(VerticesListType *vertices, int *npe, int *pes)
{ 
 int i;
 int * adj;
 Vertex * vertexRecs;
 
 adj = vertices->adjArray;
 vertexRecs = vertices->vertexArray;

#if CMK_NODE_QUEUE_AVAILABLE
 *npe = vertexRecs[CmiMyNode()].degree;
 for (i=0; i<vertexRecs[CmiMyNode()].degree; i++)
       pes[i] = adj[ vertexRecs[CmiMyNode()].adjListInd + i ];
#else
 *npe = vertexRecs[CmiMyPe()].degree;
 for (i=0; i<vertexRecs[CmiMyPe()].degree; i++)
       pes[i] = adj[ vertexRecs[CmiMyPe()].adjListInd + i ];
#endif
}

static void printOut(VerticesListType *vertices)
{int i,j;
 int * adj;
 Vertex * vertexRecs;
 FILE *fp;
 char filename[40];
 
 adj = vertices->adjArray;
 vertexRecs = vertices->vertexArray;

 for (i=0; i<vertices->numVertices; i++)
   {
     /* Open graphN/graphi */
     sprintf(filename, "graph%d/graph%d", vertices->numVertices, i);
     fp = fopen(filename, "w");
     fprintf(fp, "%d ", vertexRecs[i].degree);
     for (j=0; j<vertexRecs[i].degree; j++)
       fprintf(fp, "%d ", adj[ vertexRecs[i].adjListInd + j ]);
     fprintf(fp, "\n");
     fclose(fp);
   }
}

static void initGraph(VerticesListType *graph)
{ int i;
  graph->numVertices = V;
  graph->vertexArray = (Vertex *) malloc(V*sizeof(Vertex));
  _MEMCHECK(graph->vertexArray);
  graph->adjArray = (int *) malloc(2*E*sizeof(int));
  _MEMCHECK(graph->adjArray);

  for (i=0; i< V; i++) {
    graph->vertexArray[i].degree = 0;
    graph->vertexArray[i].next = i*C;
    graph->vertexArray[i].adjListInd = i*C;
  }
}

static void enqueue(Q *q, int i);

static void diameter(VerticesListType *graph)
{
  extern Q * makeQueue(void);
  int i,j, k, v, w, start;
  int *distance;
  int *histogram;
  Q * q;
  int dia;
  float average;

  distance = (int *)calloc(V, sizeof(int));
  histogram = (int *)calloc(V, sizeof(int));

  for (i=0; i<V; i++) {
    histogram[i] = 0; 
  }
  
  dia = 0;
  average = 0.0;
  q = makeQueue();
  for (i=0; i<V; i++) {
    /* run non-weighted shortes distance algorithm for each vertex i */
    for (j=0; j<V; j++) distance[j] = -1;
    distance[i] = 0;
    enqueue(q, i);
    while (! (isEmpty(q))) {
      v = dequeue(q);
      
      start=graph->vertexArray[v].adjListInd;
      for (k=0; k< graph->vertexArray[i].degree; k++) {
    w = graph->adjArray[k+start];
    if (distance[w] == -1) {
      distance[w] = distance[v] + 1;
      enqueue(q, w);
    }
      }
    }
    for (j=0; j<V; j++) {
      if (distance[j] > dia) dia = distance[j];
      average += distance[j];
      histogram[ distance[j]]++;
    }
  }
  average = average / (V*V);
  printf("the diameter is: %d, average internode distance = %f\n", 
     dia, average);
  /*for (i = 0; i< 6; i++) printf("histo[%d] = %d\n", i, histogram[i]);*/
  free(distance);
  free(histogram);
}

/* ------------------------------------------------- */
/* The queue ADT */

static Q * makeQueue(void)
{
  Q *q = (Q *) malloc(sizeof(Q));
  _MEMCHECK(q);
  q->size = VMAX;
  q->numElements = 0;
  q->head = 1;
  q->tail = 0;
  q->buf = (int *) malloc(VMAX*sizeof(int));
  _MEMCHECK(q->buf);
  return q;
}

static void enqueue(Q * q, int i) {
  q->tail++;
  if (q->tail == q->size) q->tail = 0; /* no overflows possible */
  q->buf[q->tail] = i;
  q->numElements++;
}

static int dequeue(Q *q) {
  int r;
  r = q->buf[q->head++];
  if (q->head == q->size) q->head = 0;
  q->numElements--;
  return r;
}

static int isEmpty(Q * q) {
  return (q->numElements == 0) ;
}

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