Go to specific line in a file (suggest better way)

Question

I made a program to output a line of text from file .
The program accepts line number and prints whatever text is on that line.

I want to know if there is a better way to do this? I'm using getline function to read a line from file but I only print the last line read.....So I think that's not efficient way to do if files are larger. (0_o)

I can't link any other files so I'm just using source file to perform actions.... checkout code and suggest better way.
https://code.sololearn.com/cI3eoGoKb0fD/?ref=app

Thank you.