Find min value in 2d array with MPI - c

Question

Recently began to study MPI technology
The task is to find the minimum value in the matrix.
Search itself parallelize for faster work.
But I can’t put my mind to how to make a parallel version from the sequential version of the program
I ask for help
#include <stdio.h>
#include "mpi.h"
#include <stdio.h>
#include <stdlib.h>
int main(int argc,char *argv[])
{
int rows, cols, min, value, n;
int done = 0, numprocs, rank, i, j;
srand(time(NULL));
double startwtime = 0.0, endwtime;
int namelen;
char processor_name[MPI_MAX_PROCESSOR_NAME];
MPI_Init(&argc,&argv);
MPI_Comm_size(MPI_COMM_WORLD,&numprocs);
MPI_Comm_rank(MPI_COMM_WORLD,&rank);
MPI_Get_processor_name(processor_name,&namelen);
while (!done) {
if (rank == 0) {
printf("Enter the height/width of the matrix\n");
scanf("%d",&rows);
scanf("%d",&cols);
startwtime = MPI_Wtime();
}
if (rows == 0 || cols == 0) {
done = 1;
} else {
int **arr = (int **) malloc(rows * sizeof(int*)); //creating 2d array
for (i = 0; i < rows; i++) {
arr[i] = (int *) malloc(cols * sizeof(int));
}
for (i = 0; i < rows; i++) { //Array filling
for (j = 0; j < cols; j++) {
arr[i][j] = rand();
}
}
for (i = 0; i < rows; i++) { // output of the array to the screen for clarity
for (j = 0; j < cols; j++) {
printf("%d\n",arr[i][j]);
}
}
min = arr[0][0];
for (i = 0; i < rows; i++) { //find min value
for (j = 0; j < cols; j++) { //
if(min > arr[i][j]){min = arr[i][j];} //need to parallize
}
}
if (rank == 0) {
endwtime = MPI_Wtime();
printf("min = %d\n", min);
printf("wall clock time = %f\n", endwtime-startwtime);
fflush( stdout );
for(i = 0; i < rows; i++) {
free(arr[i]);
}
free(arr);
}
}
}
MPI_Finalize();
return 0;
}
Sorry for my bad English
I am hope for your help
UPD: Added a similar function, but the program gives out garbage. It seems to me that this is due to the creation of an array based on pointers. And most likely I misused the functions
MPI_Scatter (&arr[0][0], rows*cols/numprocs, MPI_INT, &arr[rows][cols], rows*cols/numprocs, MPI_INT, 0, MPI_COMM_WORLD);
min = arr[0][0];
for (i = 0; i < rows; i++) {
for (j = 0; j < cols; j++) {
min = arr[i][j];
}
}
MPI_Reduce(&min, &value, rows*cols/numprocs, MPI_INT, MPI_MIN, 0, MPI_COMM_WORLD);