add new solutions

solutions/0/q8/solution.go

@@ -0,0 +1,56 @@
+package q8
+
+const (
+	MIN = -(1 << 31)
+	MAX = 1<<31 - 1
+)
+
+func myAtoi(s string) int {
+	sign := 0
+	num := 0
+
+Loop:
+	for i := range len(s) {
+		c := s[i]
+
+		switch c {
+		case '-':
+			if sign != 0 {
+				break Loop
+			}
+			sign = -1
+
+		case '+':
+			if sign != 0 {
+				break Loop
+			}
+			sign = 1
+
+		case ' ':
+			if sign != 0 {
+				break Loop
+			}
+
+		default:
+			if c < '0' || c > '9' {
+				break Loop
+			}
+			if sign == 0 {
+				sign = 1
+			}
+			num = num*10 + int(c-'0')
+			if sign*num < MIN {
+				num = -MIN
+				break Loop
+			}
+			if sign*num > MAX {
+				num = MAX
+				break Loop
+			}
+		}
+	}
+
+	return sign * num
+}
+
+var _ = myAtoi