Implemented cacheSolve

Author: ikohut

cachematrix.R

@@ -1,15 +1,37 @@
-## Put comments here that give an overall description of what your
-## functions do
-
-## Write a short comment describing this function
-
-makeCacheMatrix <- function(x = matrix()) {
-
-}
-
-
-## Write a short comment describing this function
-
-cacheSolve <- function(x, ...) {
-        ## Return a matrix that is the inverse of 'x'
-}
+## The solution implements an approach to speedup such time-consuming operation
+## as matrix inverse (using "solve")
+## Assumption: input matrix is invertible 
+
+## Function makeCacheMatrix creates a special "matrix" object that can cache 
+## its inverse.
+
+makeCacheMatrix <- function(x = matrix()) {
+    mi <- NULL
+    set <- function(y) {
+        x <<- y
+        mi <<- NULL
+    }
+    get <- function() x
+    setInverse <- function(inversed) mi <<- inversed
+    getInverse <- function() mi
+    list(set = set, get = get,
+        setInverse = setInverse,
+        getInverse = getInverse)
+}
+
+
+## Function "cacheSolve" computes the inverse of the special "matrix" returned by
+## "makeCacheMatrix". If the inverse has already been calculated and the matrix
+## has not changed, then cacheSolve retrieves the inverse from the cache.
+
+cacheSolve <- function(x, ...) {
+    mi <- x$getInverse()
+    if(!is.null(mi)) {
+        message("getting cached data")
+        return(mi)
+    }
+    data <- x$get()
+    mi <- solve(data, ...)
+    x$setInverse(mi)
+    mi
+}