Read txt file each letter count - c

Question

i tried to read a txt file and count all a to z each letter count without considering uppercase and lowercase. i need to ignore other characters and spaces. but i cannot get correct number count with changig the process count. process need to be in between 1 to 100. with 2 number of process it will show correct count but when i increase the number it shows wrong count.
//FILE READING USING MPI FUNCTION
#include <stdio.h>
#include <mpi.h>
#include <stdlib.h>
#include <string.h>
int main(int argc, char* argv[]) {
int size;
int rank;
int tag = 0;
int start;
int letterCounts[26];
MPI_Status status;
int chunksize;
MPI_Offset file_size;
MPI_Init(&argc, &argv);
MPI_Comm_size(MPI_COMM_WORLD, &size);
MPI_Comm_rank(MPI_COMM_WORLD, &rank);
if(size >= 101){
printf(" Process failed");
MPI_Abort(MPI_COMM_WORLD, 1);
}
MPI_File file;
MPI_File_open(MPI_COMM_WORLD, "warandpeace.txt", MPI_MODE_RDONLY, MPI_INFO_NULL, &file);
if (file == MPI_FILE_NULL) {
printf("Error opening file!\n");
MPI_Abort(MPI_COMM_WORLD, 1);
}
// find the file size
MPI_File_get_size(file, &file_size);
//printf("Process %d: filesize %d\n", rank,file_size);
// Allocate a buffer to hold the file contents
char* buffer = (char*)malloc(file_size * sizeof(char));
if(rank==0){
// Read the file into the buffer
MPI_File_read(file, buffer, file_size, MPI_CHAR, MPI_STATUS_IGNORE);
// Close the file
//MPI_File_close(&file);
//free(buffer);
//deviding the file
chunksize = file_size/(size - 1);
//printf("chunksize is %d\n",chunksize);
int end = chunksize;
for (int i = 1; i < size; i++) {
int start = 0;
MPI_Send(&buffer[start], end - start, MPI_CHAR, i, 0, MPI_COMM_WORLD);
start = end;
end += chunksize;
if (i == size - 2) {
end = file_size;
}
printf("destination rank %d: filesize%d: chunksize = %d\n", i,file_size, chunksize);
}
}
else{
// Receive the file size from process 0
//long file_size;
// Allocate memory for the chunks
//int chunksize = file_size / size;
char* buffer = (char*)malloc(file_size * sizeof(char));
// Receive the chunk of the file and count the letters
MPI_Recv(buffer, file_size, MPI_CHAR, 0, 0, MPI_COMM_WORLD, &status);
int count;
MPI_Get_count(&status, MPI_CHAR, &count);
printf("count%d: status = %d\n", count, status);
for (int j = 0; j < count; j++) {
char c = buffer[j];
if (c >= 'a' && c <= 'z') {
letterCounts[c - 'a']++;
}
else if (c >= 'A' && c <= 'Z') {
letterCounts[c - 'A']++;
}
}
}
// Reduce the counts from each process to get the total count
int totalCounts[26];
MPI_Reduce(letterCounts, totalCounts, 26, MPI_INT, MPI_SUM, 0, MPI_COMM_WORLD);
if (rank == 0) {
// Print the total counts
for (int i = 0; i < 26; i++) {
printf("%c: %d\n", 'a' + i, totalCounts[i]);
}
}
MPI_Finalize();
return 0;
}