So many problems in so few lines. I probably forget some: argv[0] is the program name, not the first argument; if you want to read in a variable, you have to allocate its memory one never loops on feof, one loops on an IO function until it fails, feof then serves to determinate the reason … Read more
ignore does exactly what the name implies. It doesn’t “throw away” something you don’t need. Instead, it ignores the number of characters you specify when you call it, up to the char you specify as a delimiter. It works with both input and output buffers. Essentially, for std::cin statements you use ignore before you do … Read more
tl;dr: Because of different default settings in C++ requiring more system calls. By default, cin is synchronized with stdio, which causes it to avoid any input buffering. If you add this to the top of your main, you should see much better performance: std::ios_base::sync_with_stdio(false); Normally, when an input stream is buffered, instead of reading one … Read more