程序代码：

//杨辉三角。。。。

#include < stdio.h >
#include < stdlib.h >
#define N 11
int main ( void )
{
    int i, j, a[N][N];
    for ( i = 1;i <N; i++ )
    {
        a[i][1] = 1;
        a[i][i] = 1;
    }
    for ( i = 3; i <N;i++ )
        for ( j = 2; j <= i-1; j++ )
            a[i][j] = a[i-1][j] + a[i-1][j-1];
    for ( i = 1; i <N ; i++ )
    {
        for ( j = 1; j <=i; j++ )
            printf ( "%5d", a[i][j] );
        printf ( "\n" );
    }
    system ( "pause" );
    return ( 0 );

}