Permutation matrices research.
revert: Revert is_costas parallelization.
+9
-14
+9
-14
src/lib/lib.cpp
+9
-14
src/lib/lib.cpp
···
24
24
return true;
25
25
}
26
26
27
-
// TODO: (fix): When is_costas receives a non-const qualified vector it may
28
-
// return an incorrect result.
29
27
fn is_costas(Vec<UInt> const& vec) -> Bool {
30
28
using Set = std::unordered_set<UInt>;
31
29
32
30
if (Set(vec.cbegin(), vec.cend()).size() != vec.size())
33
31
return false;
34
32
35
-
bool flag = false;
36
-
auto const l = vec.size() / 2 + 2;
37
-
#pragma omp parallel for shared(flag)
38
-
for (Size h = 1; h < l; ++h) {
33
+
let n = vec.size();
34
+
var flag = false;
35
+
for (Size k = 1; k < n; ++k) {
39
36
if (flag)
40
-
continue;
41
-
var set = Set(l - h);
42
-
for (Size i = h - 1; i < l - 1; ++i) {
43
-
let result = vec[(h + i) % l] - vec[i];
44
-
if (set.contains(result)) {
45
-
#pragma omp atomic write
37
+
break;
38
+
var seen = Vec<Bool>(2 * n, false);
39
+
for (Size i = 0; i < n - k; ++i) {
40
+
let result = Int(vec[(i + k) % n]) - Int(vec[i]) + Int(n);
41
+
if (not seen[result]) {
46
42
flag = true;
47
43
break;
48
44
}
49
-
set.insert(vec[(h + i) % l] - vec[i]);
50
45
}
51
46
}
52
-
return !flag;
47
+
return flag;
53
48
}
54
49
55
50
fn costas_nxn(Vec<UInt> v) -> Vec<Vec<UInt>> {