The Google autonomous car validation team uses a tool that gives the lines of code that are covered by a test case. They want to select the fewest test cases to validate the entire code. Either give a...

The Google autonomous car validation team uses a tool that gives the lines of code that are covered by a test case. They want to select the fewest test cases to validate the entire code. Either give a polynomial algorithm to find a set which has fewest test cases that cover the entire code or show it is NP-hard.