teamnote history merge

2025fall/source/Math/MillerRabin.cpp

@@ -0,0 +1,26 @@
+ll pow(ll a, ll b, ll mod) {
+    ll ret = 1;
+    for(int st=0; (1LL<<st) <= b; st++) {
+        if((1LL<<st) & b) ret=(lll)ret*a%mod;
+        a=(lll)a*a%mod;
+    }
+    return ret;
+}
+bool miller(ll n, ll a) {
+    if(n == a) return true;
+    ll x = n-1;
+    if(pow(a, x, n) != 1) return false;
+    while(x%2==0) {
+        x/=2;
+        ll t = pow(a, x, n);
+        if(t!=1 and t!=n-1) return false;
+        if(t==n-1) return true;
+    }
+    return true;
+}
+bool is_p(ll n) {
+    if(n<=2) return n==2;
+    vi D = {2, 3, 5, 7, 11, 13, 17, 23, 29, 31, 37};
+    for(auto i:D) if(!miller(n, i)) return false;
+    return true;
+}