/* File:       
 *    ex3.4_mpi_output_inorder.c
 *
 * Description:
 *    Print messages in process rank order:  first message from 0, then
 *    message from 1, etc. 
 *
 * Compile:    
 *    mpicc -g -Wall -o ex3.4_mpi_output_inorder ex3.4_mpi_output_inorder.c
 * Usage:        
 *    mpiexec -n <number of processes> ./ex3.4_mpi_output_inorder
 *
 * Input:
 *    none
 * Output:
 *    none
 *
 * IPP:  
 *    Exercise 3.4
 *
 */
#include <stdio.h>
#include <string.h>
#include <mpi.h> 

const int MAX_STRING = 100;

int main(void) {
   int src;
   char msg[MAX_STRING];
   
   int my_rank, comm_sz;
   MPI_Comm comm;
   
   MPI_Init(NULL, NULL); 
   comm = MPI_COMM_WORLD;
   MPI_Comm_size(MPI_COMM_WORLD, &comm_sz); 
   MPI_Comm_rank(MPI_COMM_WORLD, &my_rank); 
   
   if (my_rank == 0) {
      printf("Proc %d of %d > Does anyone have a toothpick?\n",
            my_rank, comm_sz);
      for(src = 1; src < comm_sz; src++){
         MPI_Recv(msg, MAX_STRING, MPI_CHAR, src, 0, comm, 
               MPI_STATUS_IGNORE);
         printf("%s", msg);
      }
   } else {
      sprintf(msg, "Proc %d of %d > Does anyone have a toothpick?\n",
            my_rank, comm_sz);
      MPI_Send(msg, strlen(msg)+1, MPI_CHAR, 0, 0, comm);
   }
   

   MPI_Finalize();
   return 0;
}  /* main */