Module:Utils: Difference between revisions

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@@ Line 55: / Line 55: @@
 -- returns true if integer n is prime; cannot be used with {{#invoke:}}
 function p.is_prime(n)
-  local cached = primes[n]
+	local cached = primes[n]
-  if cached ~= nil then
+	if cached ~= nil then
-    return cached
+		return cached
-  end
+	end
-  for i = 2, math.sqrt(n) do
+	for i = 2, math.sqrt(n) do
-    if n % i == 0 then
+		if n % i == 0 then
-      primes[n] = false
+			primes[n] = false
-      return false
+			return false
-    end
+		end
-  end
+	end
-  primes[n] = true
+	primes[n] = true
-  return true
+	return true
 end
@@ Line 76: / Line 76: @@
 function p._prime_factorization(n)
-  local factors, powers = {}, {}
+	local factors, powers = {}, {}
-  local new_number = n
+	local new_number = n
-  for i = 2, n do
+	for i = 2, n do
-    if p.is_prime(i) then
+		if p.is_prime(i) then
-      if new_number % i == 0 then
+			if new_number % i == 0 then
-        factors[#factors + 1] = i
+				factors[#factors + 1] = i
-        powers[#factors] = 0
+				powers[#factors] = 1
-      end
+			end
-      while new_number % i == 0 do
+			while new_number % i == 0 do
-        powers[#factors] = powers[#factors] + 1
+				powers[#factors] = powers[#factors] + 1
-        new_number = new_number / i
+				new_number = new_number / i
-      end
+			end
-      powers[#factors] = factors[#factors] .. "<sup>" .. powers[#factors] .. "</sup>"
+			if powers[#factors] > 1 then
-    end
+				powers[#factors] = factors[#factors] .. "<sup>" .. powers[#factors] .. "</sup>"
-    if new_number == 1 then
+			end
-      break
+		end
-    end
+		if new_number == 1 then
-  end
+			break
-  return table.concat(powers, " × ")
+		end
+	end
+	return table.concat(powers, " × ")
 end
 return p