From 4b3ff681fe0829268cb950a974ae4a0d3f4d05fd Mon Sep 17 00:00:00 2001
From: boolpurist <fnaumann@posteo.de>
Date: Tue, 6 Aug 2024 11:11:43 +0200
Subject: [PATCH] Ensured correctness by using a dequeue for subsequent path
 walking

---
 src/lib.rs | 18 ++++++++++++------
 1 file changed, 12 insertions(+), 6 deletions(-)

diff --git a/src/lib.rs b/src/lib.rs
index 4b96a49..2bed49c 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,6 +1,8 @@
 pub struct Solution;
 
 // Copy from here for submitting this solution to leet code
+
+use std::collections::VecDeque;
 impl Solution {
     pub fn can_jump(nums: Vec<i32>) -> bool {
         Solution::idiom_can_jump(&nums)
@@ -30,13 +32,14 @@ impl Solution {
             return false;
         }
         let target_val = (nums.len() - 1) as i32;
-        let mut next_nodes = Vec::from([(0, nums[0])]);
+        // Using a dequeue ensures that every index is visited
+        let mut next_nodes = VecDeque::from([(0, nums[0])]);
         // index visited yet
-        let mut visted_indices = -1;
+        let mut greatest_visted_indices = -1;
         if Self::check_with_target_value(target_val, 0) {
             return true;
         }
-        while let Some(next_node) = next_nodes.pop() {
+        while let Some(next_node) = next_nodes.pop_front() {
             let (index, steps) = next_node;
             let max_jump_height = index + steps;
             if Self::check_with_target_value(target_val, max_jump_height) {
@@ -45,12 +48,15 @@ impl Solution {
             // It can start at 1 because the every index was checked in previous path walking
             for next_to_check in 1..=steps {
                 let to_add = index + next_to_check;
-                if visted_indices >= to_add {
+                // Going left to right and using a dequeue
+                // for subsequent path walking ensures that
+                // every index before to_add was visited.
+                if greatest_visted_indices >= to_add {
                     // already visited this index
                     continue;
                 }
-                visted_indices = to_add;
-                next_nodes.push((to_add, nums[to_add as usize]));
+                greatest_visted_indices = to_add;
+                next_nodes.push_front((to_add, nums[to_add as usize]));
             }
         }
         false