add sol

leetcode/402.RemoveKDigits/sol.go

@@ -0,0 +1,33 @@
+// https://leetcode.com/problems/remove-k-digits
+
+package main
+
+import (
+	"fmt"
+)
+
+func removeKdigits(num string, k int) string {
+	stk, remain := make([]byte, 0), len(num)-k
+	for i := 0; i < len(num); i++ {
+		n := len(stk)
+		for k > 0 && n > 0 && stk[n-1] > num[i] {
+			stk = stk[:n-1]
+			n, k = n-1, k-1
+		}
+		stk = append(stk, num[i])
+	}
+
+	for i := 0; i < len(stk) && i < remain; i++ {
+		if stk[i] != '0' {
+			return string(stk[i:remain])
+		}
+	}
+	return "0"
+}
+
+func main() {
+	num := "1432219"
+	k := 3
+
+	fmt.Println(removeKdigits(num, k))
+}