broadcast - MPI own code to find the minimum value in a vector -

I am trying to write my own MPI function which will calculate the smallest number in the vector and all the processes Will broadcast. I treat the processes in the form of a binary tree, and in the form of minimal, I go from the leaves to the root. Then I send messages to the leaves through the roots of my children. But I get a segmentation mistake when I try to get the minimum value with rank in 0 to 3 with only 4 processes from Rank 1 in the process of left child (Process Rank 3) in execution.

  zero communication: ReduceMin (double and partial, double and total minutes) {MPI_Barrier (MPI_COMM_WORLD); Double * left child; * right child; LeftChild = (double *) Molec (s) (double)); RightChild = (double *) malloc (sizeof (double)); LeftChild [0] = rightChild [0] = 1e10; Cout & lt; & Lt; "Com Redman:" & lt; & Lt; MyRank & lt; & Lt; "" & Lt; PartialMin & lt; & Lt; "" & Lt; & Lt; NProcs & lt; & Lt; Andal; MPI_Status * Status; // MPI_Recv 2 * i + 1 amd 2 * i + 2 if (nProcs & gt; 2 * myRank + 1) {cout & lt; & Lt; MyRank & lt; & Lt; "Waiting From" & lt; & Lt; 2 * myRank + 1 & lt; & Lt; "For" & lt; & Lt; LeftChild [0] & lt; & Lt; Endl; MPI_Recv ((Zero *) and Left Child [0], 1, MPIDouble, 2 * Micrank + 1, 2 * Micrank + 1, MPIKMM_Worl, Status); // SEG Falat here and lieutenant; & Lt; MyRank & lt; & Lt; "Met" & lt; & Lt; 2 * myRank + 1 & lt; & Lt; Andal; } If (nProcs & gt; 2 * myRank + 2) {cout & lt; & Lt; MyRank & lt; & Lt; "Wait with" & lt; & Lt; 2 * myRank + 2 & lt; & Lt; Andal; MPI_Recv ((Zero *) Right Hair, 1, MPI_ DOUBLE, 2 * Micrank +2, 2 * Micrank +2, MPICM_AVRLD, Position); Cout & lt; & Lt; MyRank & lt; & Lt; "Met" & lt; & Lt; 2 * myRank + 1 & lt; & Lt; Andal; } // This amount is cited by & lt; & Lt; MyRank & lt; & Lt; "Search for a minute" & lt; & Lt; Endl; Double Mmin = Minute (Min (Left Shield [0], Right Shield [0]), Partial Pisces; // MPI_Send to (i + 1) / 2-1 if (MyReank! = 0) {cout & lt; Myrank & lt; & Lt; "Send" & lt; & Lt; MyMin & lt; & Lt; "To" & lt; & Lt; (Micrank + 1) / 2 -1 & lt; & Lt; Endl; MPI_Send ((Zero *) and Mimine, 1, MPI DOUBLE, (Micrank + 1) / 2 - 1, Myrnank, MPIKMM_WORLD); } Double Min; // from MPI_Recv (i + 1) / 2-1 if (myrank! = 0) {cout & lt; Myrank & lt; & Lt; "Waiting for" & lt; & Lt; (MyRank + 1) / 2-1 & lt; & Lt; Endl; MPI_Recv ((zero *) and min, 1, mpidoubable, (micrank + 1) / 2 - 1, (micrank + 1/2 - 1, mpcmm_wire, position); Cout & lt; & Lt; Myrank & lt; & Lt; "Met" & lt; & Lt; (MyRank + 1) / 2-1 & lt; & Lt; Andal; } Kummin = minutes; // MPI_send to 2 * i + 1 and 2 * i + 2 if (nProcs & gt; 2 * myRank + 1) {cout & lt; Micrank & lt; & Lt; "Sending" & lt; & Lt; 2 * myRank + 1 & lt; & Lt; Endl; MPI_Send (Zero *) & amp; minute, 1, MPI_ DOUBLE, 2 * myRank + 1, MyReanc, MPIKMM_viral); } If (nProcs & gt; 2 * myRank + 2) {cout & lt; Myrank & lt; & Lt; "Sending" & lt; & Lt; 2 * myRank + 1 & lt; & Lt; Endl; MPI_Send (Zero *) and amp; minute, 1, MPIDouble, 2 * Micrank + 2, Myrnank, MPIKMM_WORLD); }}   
 PS: I know that I can use  
  MPI_Barrier (MPI_COMM_WORLD); MPI_Reduce ((Zero *) and Partial Minute, (Zero *) and Total Mean, 1, MPI_ DOUBLE, MPIMIN, 0, MPIKMM_WORLD); MPIBcast ((Zero *) and Total Mean, 1, MPI_ DOUBLE, 0, MPI_ COMM_WORLD);   
 But I want to write my own code for fun.   
 
 
 The way you use position logic when you receive a call, a  MPI_Status  
  MPI_Status * status; // condition declared as an indicator and never been initialized ... mpeg_req ((zeros *) and left child [0], 1, mpidoubable, 2 * micrank + 1, 2 * micrank + 1, Mpicomom_worl, status); // status is an invalid indicator   
 You should change your code to:  
  MPI_Status status; ... mpei_rakev ((zeros *) and left child [0], 1, mpi_double, 2 * micrank + 1, 2 * micrank + 1, mpcmm_viral, and condition);   
 Since you do not check your code in all situations, you can pass  MPI_STATUS_IGNORE  to all calls:  
  MPI_RakeV ((* Zero *) and left child [0], 1, MPIDouble, 2 * micrank + 1, 2 * micrank + 1, MPICCM_WORLD, MPI Egages_NINRAir);