From de562b06aff4cf1b5e0119ddaaade22d4547cfbb Mon Sep 17 00:00:00 2001
From: Adrian Quek <softwaredjinn@softwaredjinn.com>
Date: Sun, 27 Sep 2015 15:30:56 +0800
Subject: [PATCH 1/2] Implemented the solution.

---
 cachematrix.R | 22 +++++++++++++++++++++-
 1 file changed, 21 insertions(+), 1 deletion(-)

diff --git a/cachematrix.R b/cachematrix.R
index a50be65aa44..3a56d8003dc 100644
--- a/cachematrix.R
+++ b/cachematrix.R
@@ -4,6 +4,17 @@
 ## Write a short comment describing this function
 
 makeCacheMatrix <- function(x = matrix()) {
+    s <- NULL
+    set <- function(y) {
+            x <<- y
+            s <<- NULL
+    }
+    get <- function() x
+    setinverse <- function(inverse) s <<- inverse
+    getinverse <- function() s
+    list(set = set, get = get,
+            setinverse = setinverse,
+            getinverse = getinverse)
 
 }
 
@@ -11,5 +22,14 @@ makeCacheMatrix <- function(x = matrix()) {
 ## Write a short comment describing this function
 
 cacheSolve <- function(x, ...) {
-        ## Return a matrix that is the inverse of 'x'
+    ## Return a matrix that is the inverse of 'x'
+    s <- x$getinverse()
+    if(!is.null(s)){
+        message("getting cached inverse")
+        return(s)
+    }
+    data <- x$get()
+    s <- solve(data, ...)
+    x$setinverse(s)
+    s
 }

From c07074336103afee8bf13ca23c5d14726423849d Mon Sep 17 00:00:00 2001
From: Adrian Quek <softwaredjinn@softwaredjinn.com>
Date: Wed, 30 Sep 2015 22:35:16 +0800
Subject: [PATCH 2/2] Added comments. Didn't think they were necessary, but
 noticed they were part of the assessment. Oh well.

---
 cachematrix.R | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/cachematrix.R b/cachematrix.R
index 3a56d8003dc..3ff7a3c2e15 100644
--- a/cachematrix.R
+++ b/cachematrix.R
@@ -4,6 +4,11 @@
 ## Write a short comment describing this function
 
 makeCacheMatrix <- function(x = matrix()) {
+    # returns a list of functions for:
+    # - setting the matrix x
+    # - getting the matrix x
+    # - setting the inverse of the matrix x (s)
+    # - getting the inverse of the matrix x
     s <- NULL
     set <- function(y) {
             x <<- y
@@ -24,10 +29,12 @@ makeCacheMatrix <- function(x = matrix()) {
 cacheSolve <- function(x, ...) {
     ## Return a matrix that is the inverse of 'x'
     s <- x$getinverse()
+    # return cached inverse if it exists
     if(!is.null(s)){
         message("getting cached inverse")
         return(s)
     }
+    # otherwise call solve to get the inverse and set it
     data <- x$get()
     s <- solve(data, ...)
     x$setinverse(s)