blah[j] = strInput;
This is undefined behaviour because blah
is empty. Which means the compiler can make the program do anything.
When compiling with the right settings, Visual C++ makes use of that undefined behaviour in the C++ standard in order to actually detect the bug and show you this error message.
Fix the bug by using push_back
instead:
blah.push_back(strInput);
3
solved Debug Assertion Failed Vector Subscript Out of Range C++