File size: 713 Bytes
bff4ec7 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 | /*@ Extern Coq
(PrimeFactorization : Z -> list Z -> Prop)
*/
/*@ Import Coq Require Import PVbench.Algorithms.integer_divide.rocq.spec_lib */
void divide(int n, int *p)
/*@ With (original : Z)
Require
n == original &&
1 <= original && original <= INT_MAX &&
IntArray::undef_full(p, original)
Ensure
exists factors,
PrimeFactorization(original, factors) &&
IntArray::undef_seg(p, 0, 1) *
IntArray::seg(p, 1, 1 + Zlength(factors), factors) *
IntArray::undef_seg(p, 1 + Zlength(factors), original)
*/
{
int cnt = 0;
for (int i = 2; i <= n; i++) {
while (n % i == 0) {
cnt++;
p[cnt] = i;
n /= i;
}
if (n == 1) {
break;
}
}
}
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