題目描述

Given string num representing a non-negative integer num, and an integer k, return the smallest possible integer after removing k digits from num.

 

[ From : https://leetcode.com/problems/remove-k-digits/ ]

輸入格式

Given string num representing a non-negative integer num, and an integer k

Constraints:

1 <= k <= num.length <= 10⁵
num consists of only digits.
num does not have any leading zeros except for the zero itself.

輸出格式

return the smallest possible integer after removing k digits from num.

 

Samples

1432219 3

1219

10200 1

200

10 2

0

提示

Example 1:

Input: num = "1432219", k = 3
Output: "1219"
Explanation: Remove the three digits 4, 3, and 2 to form the new number 1219 which is the smallest.

Example 2:

Input: num = "10200", k = 1
Output: "200"
Explanation: Remove the leading 1 and the number is 200. Note that the output must not contain leading zeroes.

Example 3:

Input: num = "10", k = 2
Output: "0"
Explanation: Remove all the digits from the number and it is left with nothing which is 0.

備註

https://leetcode.com/problems/remove-k-digits/

原始資料

• Zero1 題號：b149
• Hydro 題號：Z1149
• Locale：zh_TW
• Display：open