Partition function P: Difference between revisions
→{{header|C++}}: added non GMP version
(Added C# version) |
(→{{header|C++}}: added non GMP version) |
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=={{header|C++}}==
===GMP version===
{{libheader|GMP}}
<lang cpp>#include <chrono>
Line 234 ⟶ 235:
elapsed time: 8.99497 milliseconds
</pre>
===Non GMP version===
{{trans|C#}}
<lang cpp>#include <chrono>
#include <iostream>
using namespace std;
using namespace chrono;
const long long Lm = (long)1e18;
const int Fm = 18;
struct LI { long long lo, ml, mh, hi, tp; };
LI set(long long s) { LI d;
d.lo = s; d.ml = d.mh = d.hi = d.tp = 0; return d; }
void inc(LI& d, LI s) { // d += s
if ((d.lo += s.lo) >= Lm) { d.ml++; d.lo -= Lm; }
if ((d.ml += s.ml) >= Lm) { d.mh++; d.ml -= Lm; }
if ((d.mh += s.mh) >= Lm) { d.hi++; d.mh -= Lm; }
if ((d.hi += s.hi) >= Lm) { d.tp++; d.hi -= Lm; }
d.tp += s.tp;
}
void dec(LI& d, LI s) { // d -= s
if ((d.lo -= s.lo) < 0) { d.ml--; d.lo += Lm; }
if ((d.ml -= s.ml) < 0) { d.mh--; d.ml += Lm; }
if ((d.mh -= s.mh) < 0) { d.hi--; d.mh += Lm; }
if ((d.hi -= s.hi) < 0) { d.tp--; d.hi += Lm; }
d.tp -= s.tp;
}
inline string sf(long long n) {
int len = Fm;
string result(len--, '0');
for (long long i = n; len >= 0 && i > 0; --len, i /= 10)
result[len] = '0' + i % 10;
return result;
}
string fmt(LI x) { // returns formatted string value of x
if (x.tp > 0) return to_string(x.tp) + sf(x.hi) + sf(x.mh) + sf(x.ml) + sf(x.lo);
if (x.hi > 0) return to_string(x.hi) + sf(x.mh) + sf(x.ml) + sf(x.lo);
if (x.mh > 0) return to_string(x.mh) + sf(x.ml) + sf(x.lo);
if (x.ml > 0) return to_string(x.ml) + sf(x.lo);
return to_string(x.lo);
}
LI partcount(int n) { LI p[n + 1]; p[0] = set(1);
for (int i = 1; i <= n; i++) {
int k = 0, d = -2, j = i; LI x = set(0); while (true) {
if ((j -= (d += 3) - k) >= 0) inc(x, p[j]); else break;
if ((j -= ++k) >= 0) inc(x, p[j]); else break;
if ((j -= (d += 3) - k) >= 0) dec(x, p[j]); else break;
if ((j -= ++k) >= 0) dec(x, p[j]); else break;
} p[i] = x; } return p[n]; }
int main() {
auto start = steady_clock::now();
auto result = partcount(6666);
auto end = steady_clock::now();
duration<double, milli> ms(end - start);
cout << fmt(result) << " " << ms.count() << " ms";
}</lang>
{{out}}
Timing from Tio.run, but execution time can't be directly compared to the GMP version, as GMP isn't accessible at Tio.run.
<pre>193655306161707661080005073394486091998480950338405932486880600467114423441282418165863 7.32706 ms</pre>
=={{header|Delphi}}==
{{libheader| System.SysUtils}}
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