Create romanToInt.md

items/romanToInt.md

@@ -0,0 +1,57 @@
+---
+rank: 1
+link: https://leetcode.cn/problems/roman-to-integer/
+description: 罗马数字转整数
+---
+
+```golang
+func romanToInt(s string) (num int) {
+	var ok bool
+
+	for len(s) > 0 {
+		if s, ok = containAndRemove(s, "IV"); ok {
+			num += 4
+		} else if s, ok = containAndRemove(s, "IX"); ok {
+			num += 9
+		} else if s, ok = containAndRemove(s, "XL"); ok {
+			num += 40
+		} else if s, ok = containAndRemove(s, "XC"); ok {
+			num += 90
+		} else if s, ok = containAndRemove(s, "CD"); ok {
+			num += 400
+		} else if s, ok = containAndRemove(s, "CM"); ok {
+			num += 900
+		} else if s, ok = containAndRemove(s, "I"); ok {
+			num += 1
+		} else if s, ok = containAndRemove(s, "V"); ok {
+			num += 5
+		} else if s, ok = containAndRemove(s, "X"); ok {
+			num += 10
+		} else if s, ok = containAndRemove(s, "L"); ok {
+			num += 50
+		} else if s, ok = containAndRemove(s, "C"); ok {
+			num += 100
+		} else if s, ok = containAndRemove(s, "D"); ok {
+			num += 500
+		} else if s, ok = containAndRemove(s, "M"); ok {
+			num += 1000
+		} else {
+			panic("unknown char: " + s)
+		}
+	}
+	return
+}
+
+func containAndRemove(origin string, sub string) (result string, ok bool) {
+	result = origin
+	count := len(origin)
+	for i := 0; i <= count-len(sub); i++ {
+		if sub == origin[i:i+len(sub)] {
+			result = origin[0:i] + origin[i+len(sub):]
+			ok = true
+			break
+		}
+	}
+	return
+}
+```