course update of 2023-12-04 14:19:24

Algo/B2/Exercises/String exercise.md

@@ -79,6 +79,7 @@ def ispalind(s):
 
 ```python
 def dec_to_bin(n, p):
+  s = ""
   while n > 0:
     s = str(n%2) +s
     n = n//2
@@ -88,27 +89,14 @@ def dec_to_bin(n, p):
 
 def integer_to_twoscomp(n, p):
   if n < 0:
-    sign = -2
-  else:
-    sign = 1
-  s = dec_to_bin(n, p)
-  if sign == -1:
-    s2 = ""
-    i = len(s) - 1
-    while s[i] != "1":
-      s2 = "0" + s2
-      i -= 1
-    s2 = "1" + s2
-    i -= 1
-    while i >= 0:
-      if s[i] == "0":
-        s2 = "1" + s2
-      else:
-        s3 = "0" + s3
-        i -= 1
-      s = s2
-  return s
-  
+    n = power(2, p) + n
+   return dec_to_bin(n, p)
+
+def bin_to_dec(s):
+  n = 0
+  for b in s:
+    n = n * 2 + int(b)
+  return b
 ```
 
 2) 
@@ -127,3 +115,22 @@ def int_to_twoscomp(n, p):
   return dec_to_bin(n,p)
 ```
 
+## Exercise 2.2 (Frequency)
+
+```python
+def frequency(s: string):
+  count = 0
+  countInter = 0
+  elementMax = ""
+  index = 0
+  foreach elem in s:
+    for i in range(index, lenght(s)):
+      if s[i] == elem:
+        countInter += 1
+    if countInter > count:
+      count = countInter
+      elementMax = elem
+    index += 1
+  return (cout, elementMax)
+```
+