// Macro by MasuqaT (occar421) // https://github.com/occar421/ProgrammingContest/tree/master/templates/src/standard_io.rs use std::io; use std::io::{BufRead, Write}; use std::ops::{Rem, Div, Mul}; use std::fmt::Display; use std::iter::FromIterator; // From https://qiita.com/tanakh/items/0ba42c7ca36cd29d0ac8 macro_rules! input { (source = $s:expr, $($r:tt)*) => { let mut iter = $s.split_whitespace(); input_inner!{iter, $($r)*} }; (stdin = $s:expr, $($r:tt)*) => { let s = { let mut s = String::new(); $s.read_to_string(&mut s).unwrap(); s }; let mut iter = s.split_whitespace(); input_inner!{iter, $($r)*} }; } macro_rules! input_inner { ($iter:expr) => {}; ($iter:expr, ) => {}; ($iter:expr, $var:ident : $t:tt $($r:tt)*) => { let $var = read_value!($iter, $t); input_inner!{$iter $($r)*} }; } macro_rules! read_value { ($iter:expr, ( $($t:tt),* )) => { ( $(read_value!($iter, $t)),* ) }; ($iter:expr, [ $t:tt ; $len:expr ]) => { (0..$len).map(|_| read_value!($iter, $t)).collect::>() }; ($iter:expr, chars) => { read_value!($iter, String).chars().collect::>() }; ($iter:expr, usize1) => { read_value!($iter, usize) - 1 }; ($iter:expr, $t:ty) => { $iter.next().unwrap().parse::<$t>().expect("Parse error") }; } #[allow(unused_macros)] macro_rules! assert_judge { ($method:ident, $input:expr, $expected:expr) => { { let input = $input.as_bytes(); let mut output = Vec::new(); $method(&input[..], &mut output); let output = String::from_utf8(output).expect("Not UTF-8"); assert_eq!(output, $expected); } }; } #[allow(unused_macros)] macro_rules! assert_judge_with_output { ($method:ident, $input:expr) => { { let input = $input.as_bytes(); let mut output = Vec::new(); $method(&input[..], &mut output); String::from_utf8(output).expect("Not UTF-8") } }; } #[allow(unused_macros)] macro_rules! assert_eq_with_error { ($left:expr, $right:expr, $precision:expr) => ({ match (&$left, &$right, &$precision) { (left_val, right_val, precision_val) => { if !(*left_val - *precision_val < *right_val && *right_val < *left_val + *precision_val) { // The reborrows below are intentional. Without them, the stack slot for the // borrow is initialized even before the values are compared, leading to a // noticeable slow down. panic!(r#"assertion failed: `(left == right) +- precision` left: `{:?}`, right: `{:?}`, precision: `{:?}`"#, &*left_val, &*right_val, &*precision_val) } } } }); } #[allow(unused_macros)] macro_rules! assert_judge_with_error { ($method:ident, $input:expr, $expected:expr, $t:ty | $precision:expr ) => { { let input = $input.as_bytes(); let mut output = Vec::new(); $method(&input[..], &mut output); let output = String::from_utf8(output).expect("Not UTF-8"); let actual: $t = output.parse().unwrap(); let expected: $t = $expected.parse().unwrap(); assert_eq_with_error!(actual, expected, $precision); } }; } pub trait GenericInteger: Copy + PartialEq + Rem + Div + Mul { fn zero() -> Self; } macro_rules! dec_gi { () => {}; ($t:ty $(, $r:ty)*) => { impl GenericInteger for $t { #[inline] fn zero() -> Self { 0 } } dec_gi![ $( $r ),* ]; }; } dec_gi![u8, u16, u32, u64, u128, usize, i8, i16, i32, i64, i128, isize]; #[allow(dead_code)] pub fn gcd(a: T, b: T) -> T where T: GenericInteger { if b == T::zero() { a } else { gcd(b, a % b) } } #[allow(dead_code)] #[inline] pub fn lcm(a: T, b: T) -> T where T: GenericInteger { a / gcd(a, b) * b } pub trait IterExt where T: Display { fn easy_join(&mut self, separator: &str) -> String; } impl IterExt for TTrait where TItem: Display, TTrait: Iterator { #[inline] fn easy_join(&mut self, separator: &str) -> String { self.map(|i| format!("{}", i)).collect::>().join(separator) } } #[allow(unused_macros)] macro_rules! swap { ($v1:expr, $v2:expr) => { let buf = $v1; $v1 = $v2; $v2 = buf; }; } fn main() { let stdio = io::stdin(); let input = stdio.lock(); let output = io::stdout(); process(input, output); } fn process(mut reader: R, mut writer: W) -> () where R: BufRead, W: Write { input! { stdin = reader, n: usize, k: usize, xy_in: [(usize1, usize1); k], a: [usize1; n] } // naive let mut swaps: Vec<(usize, usize)> = vec![]; let goal = { let mut goal = vec![0usize; n]; for (i, t) in a.iter().enumerate() { goal[*t] = i; } goal }; let mut current = Vec::from_iter(0usize..n); for xy in xy_in.iter() { swap!(current[xy.0], current[xy.1]); } for (i, g) in goal.iter().enumerate() { let pos = current.iter().skip(i).position(|c| c == g).unwrap() + i; for j in (i..pos).rev() { swaps.push((j, j + 1)); swap!(current[j], current[j + 1]); } } writeln!(writer, "{}", swaps.len()); for swap in swaps { writeln!(writer, "{} {}", swap.0 + 1, swap.1 + 1); } } #[cfg(test)] mod tests { use super::*; use std::iter::FromIterator; #[test] fn sample1() { let input = "\ 5 6 1 2 3 4 2 3 3 4 1 2 4 5 5 1 4 3 2 "; let output = assert_judge_with_output!(process, input); input! { source = input, n: usize, k: usize, xy_in: [(usize1, usize1); k], a: [usize1; n] } input! { source = output, l: usize, xy_out: [(usize1, usize1); l], } let mut dest = Vec::from_iter(0usize..n); for xy in xy_in { swap!(dest[xy.0], dest[xy.1]); } for xy in xy_out { swap!(dest[xy.0], dest[xy.1]); } let mut result = vec![0usize; n]; for (i, t) in dest.iter().enumerate() { result[*t] = i; } assert_eq!(result, a); } #[test] fn sample2() { let input = "\ 6 4 1 2 2 3 5 6 3 4 2 6 3 1 5 4 "; let output = assert_judge_with_output!(process, input); input! { source = input, n: usize, k: usize, xy_in: [(usize1, usize1); k], a: [usize1; n] } input! { source = output, l: usize, xy_out: [(usize1, usize1); l], } let mut dest = Vec::from_iter(0usize..n); for xy in xy_in { swap!(dest[xy.0], dest[xy.1]); } for xy in xy_out { swap!(dest[xy.0], dest[xy.1]); } let mut result = vec![0usize; n]; for (i, t) in dest.iter().enumerate() { result[*t] = i; } assert_eq!(result, a); } }