哪位老哥帮忙看看这段代码是干嘛？

#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <string.h>
int a[33];
int b[33];
int main ( )
{
int i,j;
void ssort(int i,int j);
for (i=1;i<=16;i++) a[i]=i;
ssort(1,16);
for (i=1;i<=16;i++) printf("%3d",a[i]);
printf("\n");
return 0;
}
void ssort(int i,int j)
{int m,k,x;
if (j-i>1)
{m=(i+j)/2;
ssort(i,m);
ssort(m+1,j);
k=i;
for (x=i;x<=m;x++)
{b[k]=a[x];
b[k+1]=a[m+x-i+1];
k=k+2;}
for (x=i;x<=j;x++)
{a[x]=b[x];}
}
}