Magic words:
psql -U postgres
Most \d
commands support additional param of __schema__.name__
and accept wildcards like *.*
\q
: Quit/Exit\c __database__
: Connect to a database\d __table__
: Show table definition including triggers
/** | |
* Solves the n-Queen puzzle in O(n!) | |
* Let p[r] be the column of the queen on the rth row (must be exactly 1 queen per row) | |
* There also must be exactly 1 queen per column and hence p must be a permuation of (0 until i) | |
* There must be n distinct (col + diag) and n distinct (col - diag) for each queen (else bishop attacks) | |
* @return a Vector p of length n such that p[i] is the column of the queen on the ith row | |
*/ | |
def nQueens(n: Int) = (0 until n).permutations filter {p => | |
p.zipWithIndex.flatMap{case (c, d) => Seq(n + c + d, c - d)}.distinct.size == 2*n | |
} |
Magic words:
psql -U postgres
Most \d
commands support additional param of __schema__.name__
and accept wildcards like *.*
\q
: Quit/Exit\c __database__
: Connect to a database\d __table__
: Show table definition including triggers#!/bin/bash | |
#------------------------------------------------------------------------------ | |
# Name: sbtmkdirs | |
# Purpose: Create an SBT project directory structure with a few simple options. | |
# Author: Alvin Alexander, http://alvinalexander.com | |
# Info: http://alvinalexander.com/sbtmkdirs | |
# License: Creative Commons Attribution-ShareAlike 2.5 Generic | |
# http://creativecommons.org/licenses/by-sa/2.5/ | |
#------------------------------------------------------------------------------ |
# Bulk convert shapefiles to geojson using ogr2ogr | |
# For more information, see http://ben.balter.com/2013/06/26/how-to-convert-shapefiles-to-geojson-for-use-on-github/ | |
# Note: Assumes you're in a folder with one or more zip files containing shape files | |
# and Outputs as geojson with the crs:84 SRS (for use on GitHub or elsewhere) | |
#geojson conversion | |
function shp2geojson() { | |
ogr2ogr -f GeoJSON -t_srs crs:84 "$1.geojson" "$1.shp" | |
} |
package operator | |
object FunctionalPipeline { | |
class PipedObject[T] private[Functional] (value:T) | |
{ | |
def |>[R] (f : T => R) = f(this.value) | |
} | |
implicit def toPiped[T] (value:T) = new PipedObject[T](value) | |
} |
#Newbie programmer | |
def factorial(x): | |
if x == 0: | |
return 1 | |
else: | |
return x * factorial(x - 1) | |
print factorial(6) | |
#First year programmer, studied Pascal |