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feat: modular libary was updated
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numeric/numeric_mod.cpp

Lines changed: 20 additions & 14 deletions
Original file line numberDiff line numberDiff line change
@@ -1,34 +1,40 @@
1+
12
const int md = 1e9 + 7;
23

3-
template<typename T> T sub(T a, T b) { return (1LL*(a-b)%md + md) % md; }
4-
template<typename T> T add(T a, T b) { return (1LL*(a%md) + 1LL*(b%md)) % md; }
5-
template<typename T> T mul(T a, T b) { return (1LL*(a%md) * (b%md)) % md; }
4+
template<typename T> inline T add(T a, T b, const int& mod) { return (a+b>=mod)? a+b-mod : a+b; }
5+
template<typename T> inline T sub(T a, T b, const int& mod) { return (a-b<0)? a-b+mod : a-b; }
6+
template<typename T> inline T mul(T a, T b, const int& mod) { return (1LL*a*b)%mod; }
67

7-
template<typename T, typename U> T fastpow(T a, U b) {
8+
template<typename T, typename U> T fastpow(T a, U b, const int& mod) {
89
assert(0 <= b);
910
T answer = static_cast<T>(1);
1011
while (b > 0) {
11-
if (b & 1) {
12-
answer = mul(answer, a);
13-
}
14-
a = mul(a, a);
12+
if (b & 1) answer = mul(answer, a, mod);
13+
a = mul(a, a, mod);
1514
b >>= 1;
1615
}
1716
return answer;
1817
}
1918

20-
template<typename T> T inverse(T a) {
21-
a %= md;
22-
if (a < 0) a += md;
23-
T b = md, u = 0, v = 1;
19+
template<typename T> T inverse(T a, const int& mod) {
20+
a %= mod;
21+
if (a < 0) a += mod;
22+
T b = mod, u = 0, v = 1;
2423
while (a) {
2524
T t = b / a;
2625
b -= t * a; swap(a, b);
2726
u -= t * v; swap(u, v);
2827
}
2928
assert(b == 1);
30-
if (u < 0) u += md;
29+
if (u < 0) u += mod;
3130
return u;
3231
}
3332

34-
template<typename T> T division(T a, T b) { return mul(a, inverse(b)); }
33+
template<typename T> T division(T a, T b, const int& mod) { return mul(a, inverse(b, mod), mod); }
34+
35+
// Notes:
36+
// 1) a^(b^(a)) % md
37+
// is equal to:
38+
// c++ code:
39+
// int exponent = fastpow(b, c, md-1);
40+
// int answer = fastpow(a, exponent, md);

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