Changes
2 changed files (+12/-12)
-
-
@@ -40,7 +40,7 @@ rows, err := db.Query("SELECT weight FROM cards")if err != nil { panic(err) } s.build(rows, 0, N-1, 1) s.Build(rows, 0, N-1, 1) rows.Close() if *verbose {
-
@@ -58,7 +58,7 @@for { // Choose a random card x := rand.Intn(s.seg[1]) w, i := s.query(x, 0, N-1, 1) w, i := s.Query(x, 0, N-1, 1) if *verbose { fmt.Println(s.seg[1])
-
@@ -88,7 +88,7 @@ return} // Update segment tree and database s.update(i, w, 0, N-1, 1) s.Update(i, w, 0, N-1, 1) _, err = db.Exec("UPDATE cards SET weight=? WHERE idx=?", w, i) if err != nil { panic(err)
-
-
-
@@ -10,42 +10,42 @@ seg []int} // Build segment tree func (s segmentTree) build(a *sql.Rows, l, r, n int) { func (s segmentTree) Build(a *sql.Rows, l, r, n int) { if l == r { a.Next() a.Scan(&s.seg[n]) return } m := (l + r) >> 1 s.build(a, l, m, n<<1) s.build(a, m+1, r, n<<1|1) s.Build(a, l, m, n<<1) s.Build(a, m+1, r, n<<1|1) s.seg[n] = s.seg[n<<1] + s.seg[n<<1|1] } // Update value at index x func (s segmentTree) update(x, v, l, r, n int) { func (s segmentTree) Update(x, v, l, r, n int) { if l == r { s.seg[n] = v return } m := (l + r) >> 1 if x <= m { s.update(x, v, l, m, n<<1) s.Update(x, v, l, m, n<<1) } else { s.update(x, v, m+1, r, n<<1|1) s.Update(x, v, m+1, r, n<<1|1) } s.seg[n] = s.seg[n<<1] + s.seg[n<<1|1] } // Find element with prefix sum v func (s segmentTree) query(v, l, r, n int) (int, int) { func (s segmentTree) Query(v, l, r, n int) (int, int) { if l == r { return s.seg[n], l } m := (l + r) >> 1 if s.seg[n<<1] >= v { return s.query(v, l, m, n<<1) return s.Query(v, l, m, n<<1) } else { return s.query(v-s.seg[n<<1], m+1, r, n<<1|1) return s.Query(v-s.seg[n<<1], m+1, r, n<<1|1) } }
-