程序代码：

include <stdio.h>
#define N 6

int main( void )
{
    int i, j;
    
    for( i = 1; i < N; ++i, printf( "\n" ) )
    {
        for( j = 0; j < N - i; ++j )
            printf( " " );
        for( j = 0; j < i; ++j )
            printf( "%d", i );
    }
    
    return 0;
}