Merge-Sort in C Programming

Main code of merge sort:
[sourcecode language="c"]
void mergeSort(int a[], int n) {

int b[100];
int l = 1;

while(l<n) {

mergePass(a, l, n, b);
mergePass(b, 2*l, n, a);
l = l*4;
}
}
[/sourcecode]
Full code of merge sort:

[sourcecode language="c"]
#include <stdio.h>

void merge(int a[], int fi, int fl, int si, int sl, int c[], int ci) {

fl = fi + fl;
sl = si + sl;

while(fi<fl && si<sl) {
if(a[fi]<a[si])
c[ci++] = a[fi++];
else
c[ci++] = a[si++];
}
while(fi<fl)
c[ci++] = a[fi++];
while(si<sl)
c[ci++] = a[si++];
}

void mergePass(int a[], int l, int n, int b[]) {

int i, fi;
int q = n/(2*l);
int s = q*2*l;
int r = n-s;

for(i=0;i<q;i++) {
fi = i*2*l;
merge(a, fi, l, fi+l, l, b, fi);
}

if(r<=l) {
for(i=s;i<n;i++)
b[i] = a[i];
}
else
merge(a, s, l, s+l, r-l, b, s);
}

void mergeSort(int a[], int n) {

int b[100];
int l = 1;

while(l<n) {

mergePass(a, l, n, b);
mergePass(b, 2*l, n, a);
l = l*4;
}
}

void printArray(int a[], int sa){
int i;

for(i=0;i<sa;i++)
printf("%4d", a[i]);
printf("\n");
}


int main() {
int a[14] = {15,78,58,65,35,26,65,18,59,65,45,75,65,85};
int n = 14;

mergeSort(a,n);

printArray(a,n);

return 0;
}

[/sourcecode]