handle empty ranges (#98)

* panic on empty

* fix

* move to data structures

* fix

* update test

* now ACs

---------

Co-authored-by: Luke Videckis <lukevideckis@gmail.com>

Author: lrvideckis

Cargo.toml

@@ -206,11 +206,11 @@ path = "examples/helpers/lis_handmade.rs"
 
 [[example]]
 name = "range_container_aizu"
-path = "examples/helpers/range_container_aizu.rs"
+path = "examples/data_structures/range_container_aizu.rs"
 
 [[example]]
 name = "range_container_handmade"
-path = "examples/helpers/range_container_handmade.rs"
+path = "examples/data_structures/range_container_handmade.rs"
 
 [[example]]
 name = "mono_st"

examples/helpers/range_container_aizu.rs renamed to examples/data_structures/range_container_aizu.rs

@@ -1,7 +1,7 @@
 // verification-helper: PROBLEM https://onlinejudge.u-aizu.ac.jp/problems/DSL_2_D
 
 use proconio::input;
-use programming_team_code_rust::helpers::range_container::RangeContainer;
+use programming_team_code_rust::data_structures::range_container::RangeContainer;
 
 fn main() {
     input! {

examples/helpers/range_container_handmade.rs renamed to examples/data_structures/range_container_handmade.rs

@@ -1,6 +1,6 @@
 // verification-helper: PROBLEM https://onlinejudge.u-aizu.ac.jp/courses/lesson/2/ITP1/all/ITP1_1_A
 
-use programming_team_code_rust::helpers::range_container::RangeContainer;
+use programming_team_code_rust::data_structures::range_container::RangeContainer;
 use rand::{thread_rng, Rng};
 use std::collections::BTreeMap;
 
@@ -11,12 +11,11 @@ fn main() {
         let mut vis = vec![false; max_n + 1];
         let mut rc = RangeContainer::default();
         for _ in 0..100 {
-            let mut le = rng.gen_range(0..max_n);
-            let mut ri = rng.gen_range(0..max_n);
+            let mut le = rng.gen_range(0..=max_n);
+            let mut ri = rng.gen_range(0..=max_n);
             if le > ri {
                 (le, ri) = (ri, le);
             }
-            ri += 1;
             match rng.gen_range(0..2) {
                 0 => {
                     rc.insert_range(le as i32..ri as i32);

src/data_structures/mod.rs

@@ -3,6 +3,7 @@ pub mod binary_trie;
 pub mod disjoint_rmq;
 pub mod fenwick;
 pub mod lazy_seg_tree;
+pub mod range_container;
 pub mod rmq;
 pub mod seg_tree;
 pub mod trie;

src/helpers/range_container.rs renamed to src/data_structures/range_container.rs

@@ -5,7 +5,7 @@ use std::ops::Range;
 
 /// # Example
 /// ```
-/// use programming_team_code_rust::helpers::range_container::RangeContainer;
+/// use programming_team_code_rust::data_structures::range_container::RangeContainer;
 ///
 /// let mut rc = RangeContainer::default();
 /// rc.insert_range(-2..2);
@@ -45,6 +45,9 @@ impl<T: Copy + Ord> RangeContainer<T> {
     /// - Time: O(log n) ammortized
     /// - Space: O(1) ammortized
     pub fn insert_range(&mut self, mut range: Range<T>) {
+        if range.is_empty() {
+            return;
+        }
         if let Some(last_ri) = self.remove(&range) {
             range.end = std::cmp::max(range.end, last_ri);
         }
@@ -63,6 +66,9 @@ impl<T: Copy + Ord> RangeContainer<T> {
     /// - Time: O(log n) ammortized
     /// - Space: O(1) ammortized
     pub fn remove_range(&mut self, range: Range<T>) {
+        if range.is_empty() {
+            return;
+        }
         if let Some(last_ri) = self.remove(&range) {
             if range.end < last_ri {
                 self.mp.insert(range.end, last_ri);

src/helpers/mod.rs

@@ -1,5 +1,4 @@
 //! # Helpers
 pub mod compress;
 pub mod lis;
-pub mod range_container;
 pub mod unsafe_recursive_closure;