regular update

Author: coderxiang

ProjectEuler/gen_prime.ml

@@ -0,0 +1,32 @@
+let get_seq n = 
+  let rec aux acc n = 
+	if n = 0 then acc
+	else aux (n :: acc) (n - 1)
+  in
+  aux [] n
+
+
+let gen_prime n = 
+  let update x step lst = 
+	let rec aux acc cur y = 
+	  match y with
+		| [] -> List.rev acc
+		| h :: hs -> begin
+		  if cur < h then aux acc (cur + step) y
+		  else if h < cur then aux (h :: acc) cur hs else aux acc (cur + step) hs
+		end 
+	in
+	aux [] x lst
+  in
+
+  let rec aux acc lst = 
+	match lst with
+	  | [] -> List.rev acc
+	  | x :: xs -> begin
+		if x * x > n then aux (x :: acc) xs
+		else aux (x :: acc) (update (x*x) x xs)
+	  end
+  in
+  aux [] (List.tl (get_seq n))
+
+let y = gen_prime 10000000

ProjectEuler/p007.ml

@@ -0,0 +1,41 @@
+let get_seq n = 
+  let rec aux acc n = 
+	if n = 0 then acc
+	else aux (n :: acc) (n - 1)
+  in
+  aux [] n
+
+
+let gen_prime n = 
+  let update x step lst = 
+	let rec aux acc cur y = 
+	  match y with
+		| [] -> List.rev acc
+		| h :: hs -> begin
+		  if cur < h then aux acc (cur + step) y
+		  else if h < cur then aux (h :: acc) cur hs else aux acc (cur + step) hs
+		end 
+	in
+	aux [] x lst
+  in
+
+  let rec aux acc lst = 
+	match lst with
+	  | [] -> List.rev acc
+	  | x :: xs -> begin
+		if x * x > n then aux (x :: acc) xs
+		else aux (x :: acc) (update (x*x) x xs)
+	  end
+  in
+  aux [] (List.tl (get_seq n))
+
+(* n must be less than the size of x *)
+let rec get_nth n x = 
+  if n > List.length x then raise (Failure "n must not be larger than the length")
+  else   if n = 1 then List.hd x else get_nth (n - 1) (List.tl x)
+
+
+let p_list = gen_prime 1000000
+(* let ans = get_nth 10001 (gen_prime 1000000); *)
+
+

ProjectEuler/p099.py

@@ -0,0 +1,19 @@
+import urllib, math
+
+fin = urllib.urlopen ('http://projecteuler.net/project/base_exp.txt');
+
+mx = -1;
+cnt = 0;
+while True:
+	s = fin.readline();
+	if len (s) == 0:
+		break
+	[a, b] = map (int, s.split(','));
+	t = b * math.log (a);
+	cnt += 1;
+	if t > mx:
+		mx = t;
+		ans = cnt;
+print ans;
+	
+