Pseudo-random numbers/PCG32: Difference between revisions
→{{header|Delphi}}
Line 194:
for (i = 0; i < 5; i++) {
printf(" %d : %d\n", i, counts[i]);
}
return 0;
}</lang>
{{out}}
<pre>2707161783
2068313097
3122475824
2211639955
3215226955
The counts for 100,000 repetitions are:
0 : 20049
1 : 20022
2 : 20115
3 : 19809
4 : 20005</pre>
=={{header|C++}}==
{{trans|C}}
<lang cpp>#include <array>
#include <iostream>
class PCG32 {
private:
const uint64_t N = 6364136223846793005;
uint64_t state = 0x853c49e6748fea9b;
uint64_t inc = 0xda3e39cb94b95bdb;
public:
uint32_t nextInt() {
uint64_t old = state;
state = old * N + inc;
uint32_t shifted = (uint32_t)(((old >> 18) ^ old) >> 27);
uint32_t rot = old >> 59;
return (shifted >> rot) | (shifted << ((~rot + 1) & 31));
}
double nextFloat() {
return ((double)nextInt()) / (1LL << 32);
}
void seed(uint64_t seed_state, uint64_t seed_sequence) {
state = 0;
inc = (seed_sequence << 1) | 1;
nextInt();
state = state + seed_state;
nextInt();
}
};
int main() {
auto r = new PCG32();
r->seed(42, 54);
std::cout << r->nextInt() << '\n';
std::cout << r->nextInt() << '\n';
std::cout << r->nextInt() << '\n';
std::cout << r->nextInt() << '\n';
std::cout << r->nextInt() << '\n';
std::cout << '\n';
std::array<int, 5> counts{ 0, 0, 0, 0, 0 };
r->seed(987654321, 1);
for (size_t i = 0; i < 100000; i++) {
int j = (int)floor(r->nextFloat() * 5.0);
counts[j]++;
}
std::cout << "The counts for 100,000 repetitions are:\n";
for (size_t i = 0; i < counts.size(); i++) {
std::cout << " " << i << " : " << counts[i] << '\n';
}
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