Module io 

This module features utilities for reading input using the Scanner, and writing output using the Writer and wln macro.

Examples

You will typically use the test_cases() or test_case() functions, to obtain a Scanner and a Writer when solving contest problems.

Reading input of a single test

It is less common nowadays, as most contest will provide you with several test cases, but you can still do it, if you need to:

# Input:
2 3

# Output:
Sum: 5

use algorist::io::{test_case, wln};

fn main() {
    test_case(&mut |scan, w| {
        let (a, b): (i32, i32) = scan.pair();
        wln!(w, "Sum: {}", a + b);
    });
}

Reading number of test cases and processing them

Normally, in contest programming, you will have several test cases to process.

So, the input will start with a single integer t, which is the number of test cases, followed by t test case inputs.

# Input:
2
3 2
1 2

# Output:
Sum: 5
Sum: 3

use algorist::io::{test_cases, wln};

fn main() {
    test_cases(&mut |scan, w| {
        let (a, b): (i32, i32) = scan.pair();
        wln!(w, "Sum: {}", a + b);
    });
}

As you can see, the difference between reading a single test case and reading multiple test cases is minimal – you just need to call different function, with the same closure.

Macros

wln

A macro for writing a line with formatted output.

Structs

Scanner

Scanner reads buffered input and parses it into tokens.

Writer

A Writer is a wrapper around BufWriter<W> that provides a convenient interface for writing formatted output, without requiring to import std::io::Write by the client code. It is expected to be used with wln! macro.

Functions

test_case

A helper function to read a single test case from standard input, and write to standard output.

test_cases

A helper function to read multiple test cases from standard input, and write output to standard output.

wvln