:Pls help for this programing problem in c++ (standard IO without file read/write),better with some comment about why coding that way,thanks

Problem B: Decompression Time limit: 1 second Problem Description A compressed string consists of any number of pairs, where each pair consists of (number, pattern). A pattern can be a sub-string with any length, e.g. "ab". The number designates the number of repetition of the pattern.This assignment is to decompress the compressed string. For example, we will decompress "3ab" into "ababab" Input The input file consists of a number of strings, where each string is separated by a newline. Each number is between 1 and 9, and the string consists of only English characters. Each compressed string is known to be less than 1024 characters. However, the decompressed string will be longer than 1024bytes. Output Output the decompressed strings, one line for one test case Sample Input 2a3bc 1ABC3abc 2a3b5xyz1d Sample Output aabcbcbc ABCabcabcabc aabbbxyzxyzxyzxyzxyzd