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// https://quuxplusone.github.io/blog/2019/03/06/pythagorean-triples/
#include <stc/algo/coroutine.h>
#include <stdio.h>
void triples_vanilla(int n) {
for (int i = 1, c = 1;; ++c) {
for (int a = 1; a < c; ++a) {
for (int b = a; b < c; ++b) {
if (a*a + b*b == c*c) {
printf("{%d, %d, %d},\n", a, b, c);
if (++i > n) goto done;
}
}
}
}
done:;
}
struct triples {
int n;
int a, b, c;
int cco_state;
};
bool triples_next(struct triples* I) {
cco_begin(I);
for (I->c = 1;; ++I->c) {
for (I->a = 1; I->a < I->c; ++I->a) {
for (I->b = I->a; I->b < I->c; ++I->b) {
if (I->a*I->a + I->b*I->b == I->c*I->c) {
if (I->n-- == 0) cco_return;
cco_yield(true);
}
}
}
}
cco_final:
cco_end(false);
}
int main()
{
puts("Vanilla triples:");
triples_vanilla(6);
puts("\nCoroutine triples:");
struct triples t = {INT32_MAX};
while (triples_next(&t)) {
if (t.c < 100) printf("{%d, %d, %d},\n", t.a, t.b, t.c);
else cco_stop(&t);
}
}
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