From 4fa179244f189365b50ba972e9cc0d7189852639 Mon Sep 17 00:00:00 2001
From: Aram Ebtekar <aramebtech@gmail.com>
Date: Sun, 12 Apr 2020 01:11:59 -0700
Subject: [PATCH] cleaned up I/O examples

---
 src/graph/connectivity.rs |  4 ++--
 src/scanner.rs            | 50 +++++++++++++++++++--------------------
 tests/codeforces343d.rs   | 27 ++++++++++-----------
 3 files changed, 38 insertions(+), 43 deletions(-)

diff --git a/src/graph/connectivity.rs b/src/graph/connectivity.rs
index 8404268..4402e7d 100644
--- a/src/graph/connectivity.rs
+++ b/src/graph/connectivity.rs
@@ -17,8 +17,8 @@ impl ConnectivityData {
             time: 0,
             vis: vec![0; num_v].into_boxed_slice(),
             low: vec![0; num_v].into_boxed_slice(),
-            v_stack: Vec::new(),
-            e_stack: Vec::new(),
+            v_stack: vec![],
+            e_stack: vec![],
         }
     }
 
diff --git a/src/scanner.rs b/src/scanner.rs
index ae6f5a9..a57b408 100644
--- a/src/scanner.rs
+++ b/src/scanner.rs
@@ -13,7 +13,7 @@ impl<R: io::BufRead> Scanner<R> {
     pub fn new(reader: R) -> Self {
         Self {
             reader,
-            buffer: Vec::new(),
+            buffer: vec![],
         }
     }
 
@@ -46,7 +46,7 @@ impl<R: io::BufRead> UnsafeScanner<R> {
     pub fn new(reader: R) -> Self {
         Self {
             reader,
-            buf_str: Vec::new(),
+            buf_str: vec![],
             buf_iter: "".split_ascii_whitespace(),
         }
     }
@@ -84,32 +84,36 @@ pub fn writer_to_file(filename: &str) -> io::BufWriter<std::fs::File> {
 mod test {
     use super::*;
 
-    #[test]
-    fn test_in_memory_io() {
-        let input = "50 8".as_bytes();
-        let mut scan = Scanner::new(input);
-        let mut out = String::new();
-        use std::fmt::Write; // needed for writeln!()
+    fn solve<R: io::BufRead, W: io::Write>(scan: &mut Scanner<R>, out: &mut W) {
+        let x = scan.token::<i32>();
+        let y = scan.token::<i32>();
+        writeln!(out, "{} - {} = {}", x, y, x - y).ok();
+    }
 
+    fn unsafe_solve<R: io::BufRead, W: io::Write>(scan: &mut UnsafeScanner<R>, out: &mut W) {
         let x = scan.token::<i32>();
         let y = scan.token::<i32>();
-        writeln!(out, "Test {}", x - y).ok();
+        writeln!(out, "{} - {} = {}", x, y, x - y).ok();
+    }
+
+    #[test]
+    fn test_in_memory_io() {
+        let input: &[u8] = b"50 8";
+        let mut scan = Scanner::new(input);
+        let mut out = vec![];
 
-        assert_eq!(out, "Test 42\n");
+        solve(&mut scan, &mut out);
+        assert_eq!(out, b"50 - 8 = 42\n");
     }
 
     #[test]
     fn test_in_memory_unsafe() {
-        let input = "50 8".as_bytes();
+        let input: &[u8] = b"50 8";
         let mut scan = UnsafeScanner::new(input);
-        let mut out = String::new();
-        use std::fmt::Write; // needed for writeln!()
-
-        let x = scan.token::<i32>();
-        let y = scan.token::<i32>();
-        writeln!(out, "Test {}", x - y).ok();
+        let mut out = vec![];
 
-        assert_eq!(out, "Test 42\n");
+        unsafe_solve(&mut scan, &mut out);
+        assert_eq!(out, b"50 - 8 = 42\n");
     }
 
     #[test]
@@ -117,12 +121,9 @@ mod test {
         let (stdin, stdout) = (io::stdin(), io::stdout());
         let mut scan = Scanner::new(stdin.lock());
         let mut out = io::BufWriter::new(stdout.lock());
-        use io::Write; // needed for writeln!()
 
         if false {
-            let x = scan.token::<i32>();
-            let y = scan.token::<i32>();
-            writeln!(out, "Test {}", x - y).ok();
+            solve(&mut scan, &mut out);
         }
     }
 
@@ -131,10 +132,7 @@ mod test {
     fn test_panic_file() {
         let mut scan = scanner_from_file("input_file.txt");
         let mut out = writer_to_file("output_file.txt");
-        use io::Write; // needed for writeln!()
 
-        let x = scan.token::<i32>();
-        let y = scan.token::<i32>();
-        writeln!(out, "Test {}", x - y).ok();
+        solve(&mut scan, &mut out);
     }
 }
diff --git a/tests/codeforces343d.rs b/tests/codeforces343d.rs
index b4f1d94..27cac59 100644
--- a/tests/codeforces343d.rs
+++ b/tests/codeforces343d.rs
@@ -6,8 +6,9 @@ extern crate contest_algorithms;
 use contest_algorithms::graph::Graph;
 use contest_algorithms::range_query::{specs::AssignSum, StaticArq};
 use contest_algorithms::scanner::Scanner;
+use std::io;
 
-const SAMPLE_INPUT: &str = "\
+const SAMPLE_INPUT: &[u8] = b"\
 5
 1 2
 5 1
@@ -27,7 +28,7 @@ const SAMPLE_INPUT: &str = "\
 3 4
 3 5
 ";
-const SAMPLE_OUTPUT: &str = "\
+const SAMPLE_OUTPUT: &[u8] = b"\
 0
 0
 0
@@ -59,18 +60,7 @@ fn dfs(
     r[u] = *time;
 }
 
-#[test]
-fn main() {
-    use std::fmt::Write;
-    let mut scan = Scanner::new(SAMPLE_INPUT.as_bytes());
-    let mut out = String::new();
-    /* To read/write with stdin/stdout instead:
-        use std::io::{self, Write};
-        let (stdin, stdout) = (io::stdin(), io::stdout());
-        let mut scan = Scanner::new(stdin.lock());
-        let mut out = io::BufWriter::new(stdout.lock());
-    */
-
+fn solve<R: io::BufRead, W: io::Write>(scan: &mut Scanner<R>, out: &mut W) {
     let n = scan.token::<usize>();
     let mut tree = Graph::new(n, 2 * (n - 1));
     for _ in 1..n {
@@ -102,6 +92,13 @@ fn main() {
             writeln!(out, "{}", ans).ok();
         }
     }
+}
+
+#[test]
+fn main() {
+    let mut scan = Scanner::new(SAMPLE_INPUT);
+    let mut out = vec![];
+    solve(&mut scan, &mut out);
 
     assert_eq!(out, SAMPLE_OUTPUT);
-}
+}
\ No newline at end of file