Arrays being randomly overwritten in C program. Probably simple solution - c

Question

I have 4 functions that run through a text file and store the values to their designated arrays decalred at the beginning of the problem. The issue i'm having is that when I update one of the arrays the others all are never updated or are reset. So for example if I run the getkosDS function it will update the array and print out the value i am looking for. The other arrays will contain zero. However if I comment out the getkosDS function the next array (nipsDS) will update and not be zero!!! I am very confused.
#include <mpi.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
int kosND;
int kosNW;
int kosNZC;
int enronND;
int enronNW;
int enronNZC;
int nipsND;
int nipsNW;
int nipsNZC;
int nytND;
int nytNW;
int nytNZC;
int world_size;
int my_rank;
int kosDS[3430];
int nipsDS[1500];
int enronDS[39861];
int nytDS[300000];
void getKOS(){
int i;
FILE *MyFile;
char line[25];
MyFile=fopen("/home/mcconnel/BagOfWords/docword.kos.txt","r");
for(i=0; i<5; i++){
fscanf(MyFile, "%s", line);
if(i == 0){
kosND = atoi(line);
}
if(i == 1){
kosNW = atoi(line);
}
if(i == 2){
kosNZC = atoi(line);
}
}
fclose(MyFile);
}
void getEnron(){
int i;
FILE *MyFile;
char line[25];
MyFile=fopen("/home/mcconnel/BagOfWords/docword.enron.txt","r");
for(i=0; i<5; i++){
fscanf(MyFile, "%s", line);
if(i == 0){
enronND = atoi(line);
}
if(i == 1){
enronNW = atoi(line);
}
if(i == 2){
enronNZC = atoi(line);
}
}
}
void getNips(){
int i;
FILE *MyFile;
char line[25];
MyFile=fopen("/home/mcconnel/BagOfWords/docword.nips.txt","r");
for(i=0; i<5; i++){
fscanf(MyFile, "%s", line);
if(i == 0){
nipsND = atoi(line);
}
if(i == 1){
nipsNW = atoi(line);
}
if(i == 2){
nipsNZC = atoi(line);
}
}
fclose(MyFile);
}
void getNYT(){
int i;
FILE *MyFile;
char line[25];
MyFile=fopen("/home/mcconnel/BagOfWords/docword.nytimes.txt","r");
for(i=0; i<5; i++){
fscanf(MyFile, "%s", line);
if(i == 0){
nytND = atoi(line);
}
if(i == 1){
nytNW = atoi(line);
}
if(i == 2){
nytNZC = atoi(line);
}
}
fclose(MyFile);
}
void getKosDS(){
int i;
int z;
FILE *MyFile;
char line[25];
MyFile=fopen("/home/mcconnel/BagOfWords/docstart.kos.txt","r");
for(i = 0; i<3430; i++){
fscanf(MyFile, "%s", line);
if(i != 0 && i % 2 == 1){
kosDS[z] = atoi(line);
z++;
}
}
fclose(MyFile);
}
int getNipsDS(){
int i;
int z;
FILE *MyFile;
char line[25];
MyFile=fopen("/home/mcconnel/BagOfWords/docstart.nips.txt","r");
for(i = 0; i<1500; i++){
fscanf(MyFile, "%s", line);
if(i != 0 && i % 2 == 1){
nipsDS[z] = atoi(line);
z++;
}
}
fclose(MyFile);
}
int main(int argc, char** argv)
{ MPI_Init(NULL,NULL);
MPI_Comm_size(MPI_COMM_WORLD, &world_size);
// printf("\n%d", world_size);
MPI_Comm_rank(MPI_COMM_WORLD, &my_rank);
// printf("\n%d", my_rank);
if(my_rank == 0){
getKOS();
getEnron();
getNips();
getNYT();
getKosDS();
// getEnronDS();
// getNytDS();
printf("\ngetting complete\n");
printf("KOS location %d\n", kosDS[5]);
// printf("Enron location %d\n", enronDS[200]);
printf("Nips location %d\n", nipsDS[500]);
// printf("NYT location %d\n", nytDS[10000]);
}
else{
printf("\n%d \n", my_rank);
}
MPI_Finalize();
}
this is the result
KOS location 4875
Nips location 0
however if I were to comment out getKosDS the result is
KOS location 0
Nips location 28340
Craziness, if you can't tell I'm new to C

Answer 1

In getKosDS the z is uninitialized, so by writing to nipsDS[z] you are actually writing into a random memory location, invoking an undefined behavior.
Update:
The same problem is in the getNipsDS function.