Ninth job (output Triangle)

Feelings and experiences: be familiar with Pascal's triangle algorithm, emerging issues for the middle of the variable does not know how to determine the relationship between the rows and columns, and later given a specific value judgments, let me have a deeper understanding.

Output Pascal's Triangle:

#include<stdio.h>
int main()
{
 int a[10][10];
 int i,j,n;
 printf("enter n:");
 scanf("%d",&n);
 a[0][0]=1;
 for(i=0;i<n;i++)
 {
  a[i][0]=1;
  for(j=0;j<=i/2;j++)
  {
   if(j==0)
    a[i][j]=a[0][0];
   else
    a[i][j]=a[i-1][j-1]+a[i-1][j];
       a[i][i-j]=a[i][j];
  }
 }
 for(i=0;i<n;i++)
 {
  for(j=0;j<=i;j++)
   printf("%5d",a[i][j]);
  printf("\n");
 }
  return 0;
}