Compilation error : terminate called after throwing an instance of 'std::logic_error' what(): basic_string::_M_construct null not valid

Please tell me where I m going wrong. I attached the link below :

Compilation error : terminate called after throwing an instance of ‘std::logic_error’ what(): basic_string::_M_construct null not valid

at line no 21
for(int i=s.length()-1; i>=0; i–)
i should decrease

also after line no 45
you have to extact the ‘\n’ using cin.get();

Modified Code

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