C :

#include<stdio.h>
#define N 20
void CaculateYH(int a[][N],int n);
void PrintfYH(int a[][N],int n);
int main()
{
	int a[N][N]={0},n;
	scanf("%d",&n);
	CaculateYH(a,n);
	PrintfYH(a,n);
	return 0;
}
void CaculateYH(int a[][N],int n)
{
	int i,j;
	for(i=0;i<n;i++)
	{
		a[i][0]=1;
		a[i][i]=1;
	}
	for(i=2;i<n;i++)
	{
		for(j=1;j<=i-1;j++)
		{
			a[i][j]=a[i-1][j-1]+a[i-1][j];
		}
	}
}
void PrintfYH(int a[][N],int n)
{
	int i,j;
	for(i=0;i<n;i++)
	{
		for(j=0;j<=i;j++)
		{
			printf("%d ",a[i][j]);
		}
		printf("\n");
	}
}

C++ :

#include<stdio.h>
#define N 20
void CaculateYH(int a[][N],int n);
void PrintfYH(int a[][N],int n);
int main()
{
	int a[N][N]={0},n;
	scanf("%d",&n);
	CaculateYH(a,n);
	PrintfYH(a,n);
	return 0;
}
void CaculateYH(int a[][N],int n)
{
	int i,j;
	for(i=0;i<n;i++)
	{
		a[i][0]=1;
		a[i][i]=1;
	}
	for(i=2;i<n;i++)
	{
		for(j=1;j<=i-1;j++)
		{
			a[i][j]=a[i-1][j-1]+a[i-1][j];
		}
	}
}
void PrintfYH(int a[][N],int n)
{
	int i,j;
	for(i=0;i<n;i++)
	{
		for(j=0;j<=i;j++)
		{
			printf("%d ",a[i][j]);
		}
		printf("\n");
	}
}

Pascal :

program p23285;
 var
  n,i,j:longint;
  a:array[0..20,0..20] of longint;
begin
 readln(n);
 fillchar(a,sizeof(a),0);
 a[1,1]:=1;
 for i:=2 to n do
  for j:=1 to i do
   a[i,j]:=a[i-1,j-1]+a[i-1,j];
 for i:=1 to n do
  begin
   for j:=1 to i do
    write(a[i,j],' ');
   writeln;
  end;
end.