# library

This documentation is automatically generated by online-judge-tools/verification-helper

View the Project on GitHub kazunetakahashi/library

# Numbers/EulerNums.cpp

## Code

#include <iostream>
#include <vector>
using namespace std;
using ll = long long;

// ----- EulerNums -----

class EulerNums
{
static constexpr ll MAX_SIZE{1000010LL};
ll N;
vector<ll> table;

public:
EulerNums(ll N = MAX_SIZE) : N{N}
{
table.resize(N);
for (auto i = 0; i < N; i++)
{
table[i] = i;
}
for (auto i = 2; i < N; i++)
{
if (table[i] == i)
{
for (auto j = i; j < N; j += i)
{
table[j] = table[j] / i * (i - 1);
}
}
}
}

ll euler(ll n)
{
if (n < N)
{
return table[N];
}
else
{
ll res{n};
for (auto i = 2LL; i * i <= n; i++)
{
if (n % i == 0)
{
res = res / i * (i - 1);
}
for (; n % i == 0; n /= i)
{
}
}
if (n != 1)
{
res = res / n * (n - 1);
}
return res;
}
}
};



#line 1 "Numbers/EulerNums.cpp"
#include <iostream>
#include <vector>
using namespace std;
using ll = long long;

// ----- EulerNums -----

class EulerNums
{
static constexpr ll MAX_SIZE{1000010LL};
ll N;
vector<ll> table;

public:
EulerNums(ll N = MAX_SIZE) : N{N}
{
table.resize(N);
for (auto i = 0; i < N; i++)
{
table[i] = i;
}
for (auto i = 2; i < N; i++)
{
if (table[i] == i)
{
for (auto j = i; j < N; j += i)
{
table[j] = table[j] / i * (i - 1);
}
}
}
}

ll euler(ll n)
{
if (n < N)
{
return table[N];
}
else
{
ll res{n};
for (auto i = 2LL; i * i <= n; i++)
{
if (n % i == 0)
{
res = res / i * (i - 1);
}
for (; n % i == 0; n /= i)
{
}
}
if (n != 1)
{
res = res / n * (n - 1);
}
return res;
}
}
};