2016 Update

Task/Priority-queue/R/priority-queue-1.r

@@ -1,19 +1,18 @@
 PriorityQueue <- function() {
   keys <- values <- NULL
   insert <- function(key, value) {
-    temp <- c(keys, key)
-    ord <- order(temp)
-    keys <<- temp[ord]
-    values <<- c(values, list(value))[ord]
+    ord <- findInterval(key, keys)
+    keys <<- append(keys, key, ord)
+    values <<- append(values, value, ord)
   }
   pop <- function() {
-    head <- values[[1]]
+    head <- list(key=keys[1],value=values[[1]])
     values <<- values[-1]
     keys <<- keys[-1]
     return(head)
   }
   empty <- function() length(keys) == 0
-  list(insert = insert, pop = pop, empty = empty)
+  environment()
 }
 
 pq <- PriorityQueue()
@@ -23,5 +22,5 @@ pq$insert(5, "Make tea")
 pq$insert(1, "Solve RC tasks")
 pq$insert(2, "Tax return")
 while(!pq$empty()) {
-  print(pq$pop())
+  with(pq$pop(), cat(key,":",value,"\n"))
 }

Task/Priority-queue/R/priority-queue-2.r

@@ -1,5 +1,5 @@
-[1] "Solve RC tasks"
-[1] "Tax return"
-[1] "Clear drains"
-[1] "Feed cat"
-[1] "Make tea"
+1 : Solve RC tasks
+2 : Tax return
+3 : Clear drains
+4 : Feed cat
+5 : Make tea

Task/Priority-queue/R/priority-queue-3.r

@@ -1,18 +1,17 @@
 PriorityQueue <-
-  setRefClass("PriorityQueue",
-              fields = list(keys = "numeric", values = "list"),
-              methods = list(
-                insert = function(key,value) {
-                  temp <- c(keys,key)
-                  ord <- order(temp)
-                  keys <<- temp[ord]
-                  values <<- c(values,list(value))[ord]
-                },
-                pop = function() {
-                  head <- values[[1]]
-                  keys <<- keys[-1]
-                  values <<- values[-1]
-                  return(head)
-                },
-                empty = function() length(keys) == 0
+    setRefClass("PriorityQueue",
+                fields = list(keys = "numeric", values = "list"),
+                methods = list(
+                    insert = function(key,value) {
+                        insert.order <- findInterval(key, keys)
+                        keys <<- append(keys, key, insert.order)
+                        values <<- append(values, value, insert.order)
+                    },
+                    pop = function() {
+                        head <- list(key=keys[1],value=values[[1]])
+                        keys <<- keys[-1]
+                        values <<- values[-1]
+                        return(head)
+                    },
+                    empty = function() length(keys) == 0
                 ))