Problem $1.[30$ points$]$ Write a function isSorted that takes an input vector of integers called vec and return true if vec is sorted in increasing order. Write a simple test program to demonstrate that the function returns the correct values for the following vector$\{1,2,5,6\}\{5,6,0,1\}\{10\}\{10,5,10\}\{10,10,20\}\{10,10,20,5\}$