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@fujidig
fujidig / add-meta-charset.rb
Created September 5, 2016 00:34
Dir.glob("*.html").each do |fname|
str = File.read(fname)
if str !~ /<meta charset=/
str = str.sub(/<head\b[^>]*>/) {|s| s + '<meta charset="utf-8">' }
File.write(fname, str)
end
end
@fujidig
fujidig / hensel.rb
Created April 1, 2017 23:15
# sqrt(-1) in Q_5
require "mathn"
def e_p_int(x, p)
e = 0
while x % (p**e) == 0
e += 1
end
e - 1
@fujidig
fujidig / durandkerner.ts
Last active August 13, 2017 03:10
class Complex {
x: number;
y: number;
constructor(x: number, y: number) {
this.x = x;
this.y = y;
}
add(other: Complex) {
@fujidig
fujidig / image-transparent.html
Created August 12, 2017 13:57
<!-- 白黒画像を透過画像に変換する -->
<body bgcolor="blue">
<script>
let img=new Image;
img.src="hierarchy-000001.png";
img.onload=()=>{
let canvas=document.createElement("canvas");
canvas.width=img.width;
canvas.height=img.height;
let ctx=canvas.getContext("2d");
@fujidig
fujidig / jas-test.py
Created June 11, 2018 14:29
from edu.jas.arith import *
from edu.jas.poly import *
from edu.jas.gbufd import *
br = BigInteger(0)
vars = ["y", "x"]
ring = GenPolynomialRing(br, len(vars), TermOrder(TermOrder.INVLEX), vars)
a = ring.parse("x^3 - 3 x^2 - y + 1")
b = ring.parse("-x^2 + y^2 - 1")
@fujidig
fujidig / random_function_short_period_probability.cpp
Last active October 5, 2018 10:56
#include <iostream>
#include <vector>
#include <algorithm>
#include <functional>
typedef long long ll;
bool has_1_loop(std::vector<int> &v) {
@fujidig
fujidig / random_function_short_period_probability.hs
Created October 5, 2018 10:51
import Data.Ratio
fact :: Integer -> Integer
fact 0 = 1
fact n = (fact (n - 1)) * n
solve2 :: Integer -> Rational
solve2 m = sum $ map (\k -> sum [term r s | r <- [0..m], s <- [0..m], r + s == k && r + 2 * s <= m]) [1..m]
where term r s = (-1)^(r+s-1)%(2^s*(fact r)*(fact s))*(product [1-i%m | i <- [0..r+2*s-1]])
@fujidig
fujidig / myswap.hs
Created November 5, 2018 23:27
import qualified Data.Vector.Mutable as MV
import qualified Data.Vector as V
import Control.Monad.Primitive
import Control.Monad
myswap :: PrimMonad m => MV.MVector (PrimState m) a -> Int -> Int -> m ()
myswap v i j = do
a <- MV.read v i
b <- MV.read v j
MV.write v i b
@fujidig
fujidig / sylow-p.gap
Last active December 13, 2018 00:31
# 次の主張:
# π: G→G/Z(G)を標準的な射影とすれば
# φ: Syl_p(G)→Syl_p(G/Z(G)); H↦π[H]
# がwell-defined 全単射
# を小さい群に対して確かめる
list := [
["S3", SymmetricGroup(3)],
["D8", DihedralGroup(8)],
["Q8", SmallGroup(8,4)],
@fujidig
fujidig / a208231.cpp
Created August 26, 2019 08:02
#include <stdio.h>
#include <algorithm>
#include "gmp.h"
const int M = 3000;
mpz_t fact[M+1];
mpz_t binomial[M+1][M+1];
mpz_t b[M+1][M+1];
mpz_t a[M+1];