輸出hello world本身不難 但是當人們要把它做到極快/不吃memory 就需要一點技術了 hello, world

d483.c : 2ms/52KB

include <stdio.h>
int main() {
    puts("hello, world");
    return 0;
}

d483.cpp : 1ms/36KB

include <cstdio>
int main() {
    puts("hello, world");
    return 0;
}

d483.py : 16ms, 3.2MB

from sys import stdout
stdout.write("hello, world")

java很難更快

public class Hello {
    public static void main(String[] args) {
        System.out.println("hello, world");
    }
}