add new solutions

solutions/0/q12/solution.go

@@ -0,0 +1,39 @@
+package q12
+
+import "strings"
+
+var mapping = []struct {
+	string
+	int
+}{
+	{"I", 1},
+	{"IV", 4},
+	{"V", 5},
+	{"IX", 9},
+	{"X", 10},
+	{"XL", 40},
+	{"L", 50},
+	{"XC", 90},
+	{"C", 100},
+	{"CD", 400},
+	{"D", 500},
+	{"CM", 900},
+	{"M", 1000},
+}
+
+func intToRoman(num int) string {
+	b := &strings.Builder{}
+
+	for i := len(mapping) - 1; i >= 0; i-- {
+		for num >= mapping[i].int {
+			num -= mapping[i].int
+			b.WriteString(mapping[i].string)
+		}
+		if num == 0 {
+			break
+		}
+	}
+	return b.String()
+}
+
+var _ = intToRoman