diff options
Diffstat (limited to 'math/piLegendre.cpp')
| -rw-r--r-- | math/piLegendre.cpp | 23 |
1 files changed, 0 insertions, 23 deletions
diff --git a/math/piLegendre.cpp b/math/piLegendre.cpp deleted file mode 100644 index 21b974b..0000000 --- a/math/piLegendre.cpp +++ /dev/null @@ -1,23 +0,0 @@ -constexpr ll cache = 500; // requires O(cache^3)
-vector<vector<ll>> memo(cache * cache, vector<ll>(cache));
-
-ll pi(ll n);
-
-ll phi(ll n, ll k) {
- if (n <= 1 || k < 0) return 0;
- if (n <= primes[k]) return n - 1;
- if (n < N && primes[k] * primes[k] > n) return n - pi(n) + k;
- bool ok = n < cache * cache;
- if (ok && memo[n][k] > 0) return memo[n][k];
- ll res = n/primes[k] - phi(n/primes[k], k - 1) + phi(n, k - 1);
- if (ok) memo[n][k] = res;
- return res;
-}
-
-ll pi(ll n) {
- if (n < N) { // implement this as O(1) lookup for speedup!
- return distance(primes.begin(), upper_bound(all(primes), n));
- } else {
- ll k = pi(sqrtl(n) + 1);
- return n - phi(n, k) + k;
-}}
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