From ff2c184c65b7eca055cc048425c3be7b4f80be10 Mon Sep 17 00:00:00 2001
From: Toby Lane <tobylane1@gmail.com>
Date: Sun, 30 Jun 2024 00:08:20 +0200
Subject: [PATCH] added dijkstra.py file to utils

---
 utils/dijkstra.py     | 86 +++++++++++++++++++++++++++++++++++++++++++
 utils/map_splitter.py |  2 +-
 2 files changed, 87 insertions(+), 1 deletion(-)
 create mode 100644 utils/dijkstra.py

diff --git a/utils/dijkstra.py b/utils/dijkstra.py
new file mode 100644
index 0000000..846027b
--- /dev/null
+++ b/utils/dijkstra.py
@@ -0,0 +1,86 @@
+from math import inf
+
+class Edge:
+
+    length = 0
+
+    def __init__(self, start, end, length):
+        self.length = length
+        self.start = start
+        self.end = end
+
+class Node:
+
+    def __init__(self, xpos, ypos):
+        self.xpos = xpos
+        self.ypos = ypos
+
+class Graph:
+
+    def __init__(self):
+        self.edges = list()
+        self.nodes = list()
+
+    def add_node(self, xpos, ypos):
+        self.nodes.append(Node(xpos, ypos))
+    
+    def add_edge(self, start_index, end_index, length):
+        self.edges.append(Edge(start_index, end_index, length))
+
+
+def Dijkstra(graph, source_index, target_index):
+
+    n = len(graph.nodes)
+
+    if (target_index >= n):
+        return None
+
+    unvisited = list(range(n))
+
+    distances_from_start = [inf] * n
+    distances_from_start[source_index] = 0
+
+    node_sequences = [list() for i in range(n)]
+    node_sequences[source_index] = [source_index]
+
+    while(True):
+        try:
+            current_index = min(unvisited, key = lambda i: distances_from_start[i])
+        except ValueError:
+            break
+        
+        if current_index == target_index:
+            break
+
+        unvisited.remove(current_index)
+
+        for edge in filter(
+                lambda e: e.start == current_index or e.end == current_index,
+                graph.edges):
+            
+            start = current_index
+            end = edge.end if edge.start == current_index else edge.start
+
+            if end in unvisited and distances_from_start[end] > distances_from_start[start] + edge.length:
+                distances_from_start[end] = distances_from_start[start] + edge.length
+                node_sequences[end] = node_sequences[start].copy()
+                node_sequences[end].append(end)
+
+    return node_sequences[target_index]
+
+
+graph = Graph()
+
+graph.add_node(1, 2)
+graph.add_node(4, 7)
+graph.add_node(3,1)
+graph.add_node(-2,0)
+graph.add_node(0,0)
+
+graph.add_edge(0, 1, 1)
+graph.add_edge(1, 2, 2)
+graph.add_edge(2, 3, 3)
+graph.add_edge(3, 0, 1)
+graph.add_edge(1, 3, 3)
+
+print(Dijkstra(graph, 0, 5))
\ No newline at end of file
diff --git a/utils/map_splitter.py b/utils/map_splitter.py
index 002b9e3..bc818a8 100644
--- a/utils/map_splitter.py
+++ b/utils/map_splitter.py
@@ -13,7 +13,7 @@ def clamp(mn, value, mx):
 
 
 def main():
-    # 2024-06-27_21.01.45_Lycacraft_minecraft~overworld_day.png
+    # utils/2024-06-27_21.01.45_Lycacraft_minecraft~overworld_day.png
     # 6144,10240
     input_path = input("Input image: ")
     output_path = input(f"Output dir (default: {DEFAULT_PATH}): ")