From f5316545b46edfc511b628430cd883ca2c56f1ca Mon Sep 17 00:00:00 2001 From: Paul Jungeblut Date: Sat, 8 Oct 2016 23:06:01 +0200 Subject: New extended euclid code without global variables. --- math/modExp.cpp | 14 ++++++-------- 1 file changed, 6 insertions(+), 8 deletions(-) (limited to 'math/modExp.cpp') diff --git a/math/modExp.cpp b/math/modExp.cpp index cd0f982..967068c 100644 --- a/math/modExp.cpp +++ b/math/modExp.cpp @@ -1,17 +1,15 @@ // Laufzeit: O(log(b)) -ll mult_mod(ll a, ll b, ll n) { +ll multMod(ll a, ll b, ll n) { if(a == 0 || b == 0) return 0; if(b == 1) return a % n; - - if(b % 2 == 1) return (a + mult_mod(a, b-1, n)) % n; - else return mult_mod((a + a) % n, b / 2, n); + if(b % 2 == 1) return (a + multMod(a, b-1, n)) % n; + else return multMod((a + a) % n, b / 2, n); } // Laufzeit: O(log(b)) -ll pow_mod(ll a, ll b, ll n) { +ll powMod(ll a, ll b, ll n) { if(b == 0) return 1; if(b == 1) return a % n; - - if(b % 2 == 1) return mult_mod(pow_mod(a, b-1, n), a, n); - else return pow_mod(mult_mod(a, a, n), b / 2, n); + if(b % 2 == 1) return multMod(powMod(a, b-1, n), a, n); + else return powMod(multMod(a, a, n), b / 2, n); } -- cgit v1.2.3