Choose random cards

sd.go

@@ -4,6 +4,7 @@ import (
 	"database/sql"
 	"flag"
 	"fmt"
+	"math/rand"
 	"os"
 	"os/exec"
 
@@ -12,11 +13,14 @@ import (
 
 var file = flag.String("f", "cards", "cards file")
 
+var sum = 0
 var seg = []int{}
 
 func build(a *sql.Rows, l int, r int, n int) {
 	if l == r {
+		a.Next()
 		a.Scan(&seg[n])
+		sum += seg[n]
 		return
 	}
 	m := (l + r) >> 1
@@ -27,7 +31,7 @@ func build(a *sql.Rows, l int, r int, n int) {
 
 func update(x int, v int, l int, r int, n int) {
 	if l == r {
-		seg[n] += v
+		seg[n] = v
 		return
 	}
 	m := (l + r) >> 1
@@ -41,7 +45,7 @@ func update(x int, v int, l int, r int, n int) {
 
 func query(v int, l int, r int, n int) (int, int) {
 	if l == r {
-		return seg[n], n
+		return seg[n], l
 	}
 	m := (l + r) >> 1
 	if seg[n<<1] < v {
@@ -65,7 +69,7 @@ func main() {
 	seg = make([]int, 4*N)
 
 	// Build segment tree
-	rows, err := db.Query("SELECT * FROM cards")
+	rows, err := db.Query("SELECT weight FROM cards")
 	if err != nil {
 		panic(err)
 	}
@@ -80,16 +84,30 @@ func main() {
 	defer exec.Command("stty", "-F", "/dev/tty", "echo").Run()
 
 	for {
-		fmt.Println("hello world")
+		// Choose a random card
+		x := rand.Intn(sum)
+		fmt.Println(x)
+		w, i := query(x, 0, N-1, 1)
+		fmt.Println(w)
+		fmt.Println(i)
+
+		var key, val string
+		db.QueryRow("SELECT * FROM cards WHERE idx=?", i).Scan(&i, &w, &key, &val)
+		fmt.Println(key)
+		fmt.Println(val)
 
 		var b []byte = make([]byte, 1)
 		os.Stdin.Read(b)
 		if b[0] == byte('y') {
-
+			w >>= 1
+			sum -= w
 		} else if b[0] == byte('n') {
-
+			sum += w
+			w <<= 1
 		} else {
-
+			os.Exit(0)
 		}
+		update(i, w, 0, N-1, 1)
+		db.Query("UPDATE cards SET weight=? WHERE idx=?", w, i)
 	}
 }