Data commit

Task/24-game/Go/24-game.go

@@ -0,0 +1,68 @@
+package main
+
+import (
+    "fmt"
+    "math"
+    "math/rand"
+    "time"
+)
+
+func main() {
+    rand.Seed(time.Now().Unix())
+    n := make([]rune, 4)
+    for i := range n {
+        n[i] = rune(rand.Intn(9) + '1')
+    }
+    fmt.Printf("Your numbers: %c\n", n)
+    fmt.Print("Enter RPN: ")
+    var expr string
+    fmt.Scan(&expr)
+    if len(expr) != 7 {
+        fmt.Println("invalid. expression length must be 7." +
+            " (4 numbers, 3 operators, no spaces)")
+        return
+    }
+    stack := make([]float64, 0, 4)
+    for _, r := range expr {
+        if r >= '0' && r <= '9' {
+            if len(n) == 0 {
+                fmt.Println("too many numbers.")
+                return
+            }
+            i := 0
+            for n[i] != r {
+                i++
+                if i == len(n) {
+                    fmt.Println("wrong numbers.")
+                    return
+                }
+            }
+            n = append(n[:i], n[i+1:]...)
+            stack = append(stack, float64(r-'0'))
+            continue
+        }
+        if len(stack) < 2 {
+            fmt.Println("invalid expression syntax.")
+            return
+        }
+        switch r {
+        case '+':
+            stack[len(stack)-2] += stack[len(stack)-1]
+        case '-':
+            stack[len(stack)-2] -= stack[len(stack)-1]
+        case '*':
+            stack[len(stack)-2] *= stack[len(stack)-1]
+        case '/':
+            stack[len(stack)-2] /= stack[len(stack)-1]
+        default:
+            fmt.Printf("%c invalid.\n", r)
+            return
+        }
+        stack = stack[:len(stack)-1]
+    }
+    if math.Abs(stack[0]-24) > 1e-6 {
+        fmt.Println("incorrect.", stack[0], "!= 24")
+    } else {
+        fmt.Println("correct.")
+    }
+}