binary search to sqrt. go implementation

69. Sqrt(x)/main.go

@@ -0,0 +1,42 @@
+package main
+
+import "fmt"
+
+func mySqrt2(x int) int {
+	x0 := 1
+	var tem int
+	for {
+		tem = x0
+		x0 = (x0 + x/x0) / 2
+		fmt.Println(x0)
+		if tem <= x0 {
+			break
+		}
+
+	}
+	return x0
+
+}
+
+func mySqrt(x int) int {
+	if x == 0 {
+		return 0
+	}
+	left, right := 1, x
+	var mid int
+	for left+1 < right {
+		mid = (left + right) / 2
+		if mid*mid > x {
+			right = mid
+			fmt.Println("right:", right)
+		} else {
+			left = mid
+			fmt.Println("left:", left)
+		}
+	}
+	return left
+}
+
+func main() {
+	fmt.Println(mySqrt(4))
+}