Migrated from private repo

string_reversal/string_rev.c

@@ -0,0 +1,30 @@
+#include <stdio.h>
+#include <string.h>
+
+void reverseString(char *str, int start, int end) {
+  // Base case: if start index is greater or equal to end index
+  if (start >= end) {
+    return;
+  }
+
+  // Swap the characters at start and end
+  char temp = str[start];
+  str[start] = str[end];
+  str[end] = temp;
+
+  // Recursive call with modified indices
+  reverseString(str, start + 1, end - 1);
+}
+
+int main() {
+  char str[] = "Hello, World!";
+  int n = strlen(str);
+
+  printf("Original string: %s\n", str);
+
+  // Call the reverseString function
+  reverseString(str, 0, n - 1);
+
+  printf("Reversed string: %s\n", str);
+  return 0;
+}

string_reversal/string_rev.py

@@ -0,0 +1,96 @@
+from manim import *
+
+config.background_color = (33, 33, 33)
+INPUT = "PFISAWESOME" # Manim does not like spaces unfortunately
+
+class StringReversal(Scene):
+    def construct(self):
+        # Big string 
+
+        self.string = Text(INPUT, font_size=64, font="Agave Nerd Font Mono")
+        
+        # Intro animation
+        self.play(Write(self.string))
+        self.bottom = Text(f"reverse({self.string.text}, start=0, end={len(self.string)-1})", font_size=24, font="Agave Nerd Font Mono")
+        self.bottom.to_edge(DOWN).to_edge(LEFT)
+        self.play(Write(self.bottom))
+
+        # Call the recursive function
+        result = self.reverse(INPUT, 0, len(INPUT) - 1)
+        
+        # Outro animation
+        self.play(Unwrite(self.bottom))
+        self.play(FadeToColor(self.string, GREEN))
+        self.wait(4)
+        self.play(Unwrite(self.string))
+        self.wait(1)
+    
+
+    def bottom_text(self, text):
+        # Update the bottom text
+        self.play(
+            Transform(
+                self.bottom,
+                Text(
+                    text,
+                    font_size=24, 
+                    font="Agave Nerd Font Mono"
+                ).to_edge(DOWN).to_edge(LEFT)
+            )
+        )
+        self.wait(1)
+
+    # Visual swap
+    def swap_chars(self, counter):
+        # Indicate the characters we're about to swap
+        self.play(
+            Indicate(self.string[counter]),
+            Indicate(self.string[len(self.string) - counter - 1])
+        )    
+        
+        self.wait(.5)
+        # Swap the characters
+        self.play(
+            Swap(
+                self.string[counter],
+                self.string[len(self.string) - counter - 1]
+            )
+        )
+
+        self.wait(1)
+    
+    
+    def reverse(self, string, start, end, counter=0):
+        # Color the characters that we're about to swap in bottom text
+        self.bottom_text(f"reverse({string}, start={start}, end={end})")
+
+        # Base case: If we've reached the middle of the string
+        if start >= end:
+            self.play(FadeToColor(self.bottom, GREEN))
+            self.play(Unwrite(self.bottom))
+            
+            # There must be a way to set defaults for text
+            success = Text(
+                "We reached the base case!",
+                font_size=24,
+                font="Agave Nerd Font Mono"
+            ).to_edge(DOWN).to_edge(LEFT)
+
+            self.play(Write(success))
+            self.wait(1)
+            self.play(Unwrite(success))
+            return string
+        
+        # Swap first and last chars of string
+        string = list(string)
+        string[start], string[end] = string[end], string[start]
+        string = "".join(string)
+        
+
+        self.swap_chars(counter)
+        counter += 1
+        # Recursively call reverse on the substring
+        self.reverse(string, start + 1, end - 1, counter)
+
+
+