printf("%3d ",XX);

The code printf("%3d ", XX); is written in the C programming language. It uses the printf function to print the value of the variable XX as a decimal number with a minimum width of 3 characters. The %3d format specifier is used to specify the width of the output, and the "%3d " string is the format string that includes the specifier. The space after the specifier is used to separate the output from the next item that will be printed.