2016 Update

Task/Permutations/R/permutations.r

@@ -1,42 +1,42 @@
 next.perm <- function(p) {
-	n <- length(p)
-	i <- n - 1
-	r = TRUE
-	for(i in (n-1):1) {
-		if(p[i] < p[i+1]) {
-			r = FALSE
-			break
-		}
-	}
-	
-	j <- i + 1
-	k <- n
-	while(j < k) {
-		x <- p[j]
-		p[j] <- p[k]
-		p[k] <- x
-		j <- j + 1
-		k <- k - 1
-	}
-	
-	if(r) return(NULL)
-	
-	j <- n
-	while(p[j] > p[i]) j <- j - 1
-	j <- j + 1
-	
-	x <- p[i]
-	p[i] <- p[j]
-	p[j] <- x
-	return(p)
+  n <- length(p)
+  i <- n - 1
+  r = T
+  for (i in seq(n - 1, 1)) {
+    if (p[i] < p[i + 1]) {
+      r = F
+      break
+    }
+  }
+
+  j <- i + 1
+  k <- n
+  while (j < k) {
+    x <- p[j]
+    p[j] <- p[k]
+    p[k] <- x
+    j <- j + 1
+    k <- k - 1
+  }
+
+  if(r) return(NULL)
+
+  j <- n
+  while (p[j] > p[i]) j <- j - 1
+  j <- j + 1
+
+  x <- p[i]
+  p[i] <- p[j]
+  p[j] <- x
+  return(p)
 }
 
 print.perms <- function(n) {
-	p <- 1:n
-	while(!is.null(p)) {
-		cat(p,"\n")
-		p <- next.perm(p)
-	}
+  p <- 1:n
+  while (!is.null(p)) {
+    cat(p, "\n")
+    p <- next.perm(p)
+  }
 }
 
 print.perms(3)