feat(number/basis): better version

number/basis-ng.cc

@@ -0,0 +1,34 @@
+template <typename T>
+struct basis {
+    array<T, sizeof(T) * 8> p;
+    int cnt = 0;
+
+    basis(const vector<T>& v) {
+        for (auto&& x : v) {
+            insert(x);
+        }
+    }
+
+    bool insert(T x) {
+        for (size_t i = sizeof(T) * 8 - 1; ~i; --i) {
+            if (not (x >> i)) continue;
+            if (not p[i]) {
+                p[i] = x;
+                cnt += 1;
+                return true;
+            }
+            x ^= p[i];
+        }
+        return false;
+    }
+
+    vector<T> value(void) const {
+        vector<T> res;
+        for (size_t i = sizeof(T) * 8 - 1; ~i; --i) {
+            if (not p[i]) continue;
+            res.emplace_back(p[i]);
+        }
+        return res;
+    }
+};
+