[SOLVED]Why the output starting from . next iteration (next loop)

Question

https://code.sololearn.com/cmpdhRAINOVl/?ref=app

Answer 1

First call to `std::getline()` which was supposed to read value for <st>[0] doesn't read correctly because there is a left over '\n' character in the input stream.

The '\n' character was left over from the read in of values for variable <N> and <Q>.

std::cin >> N >> Q; // <- this line

Since `std::getline()` reads input until a '\n' was found; it assumed an empty line (consists of only '\n') was read in, and set <st>[0] as empty string.

To overcome this, you must clear the '\n' off the input stream by calling ignore() method from the `std::cin` object

std::cin.ignore();

Right after the line where you read value for <N> and <Q>.