Given a number, remove n characters to find the minimum number.

Ex 1: 19345 , n = 3

Outout = 13

Explanation: Removing 9,4,5 characters results in minimum number

Ex 2: 100200, n = 1

output = 200

Explanation: Removing 1 results in minimum number

The hint was to use 2 pointers method. Appreacite any solutions to this.