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recursion example

Author: pei0807

binary_search.py

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+import numpy as np
+
+array = np.random.randint(30,size=20)
+a = [15,13,14,3,8,5,27,17,7,20,6,1,4,11]
+print(len(a))
+final=0
+loop = 0
+for j in range(0,len(a)-1,1):
+    for i in range(0,len(a)-1-j,1):
+        if a[i]>a[i+1]:
+            swap = a[i+1]
+            a[i+1] = a[i]
+            a[i]= swap
+        loop = loop+1
+
+print(a)
+# print(loop)
+
+#binary search
+target = 27
+start = round(len(a) / 2)
+
+while 1:
+    if a[start]>target:
+        prev = start
+        start = start -1
+        print(prev)
+        print(start)
+    else:
+        prev = start
+        start = start+1
+
+    if start<end:
+        print(a[start])
+        print('index %i' %start)
+        break
+
+    else:
+        print('not found')
+

list_node.py

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+# Definition for singly-linked list.
+class ListNode(object):
+    def __init__(self, x):
+        self.val = x
+        self.next = None

recursive_string.py

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+
+def main():
+    s = input('Please enter desired string')
+    a = reverseString(s)
+    print('Reversed string will be: %s'%a)
+
+def reverseString(s):
+        if len(s)==0:
+            return s
+        else:
+            return reverseString(s[1:]) + s[0]
+main()
+

swap_node_in_pairs.py

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+# Given 1->2->3->4, you should return the list as 2->1->4->3.
+# Definition for singly-linked list.
+
+from list_node import ListNode
+
+def main():
+    w=ListNode(1)
+    x=ListNode(2)
+    y =ListNode(3)
+    z = ListNode(4)
+    w.next = x
+    x.next = y
+    y.next = z
+    print(w.val)
+    print(w.next.val)
+    print(w.next.next.val)
+    print(w.next.next.next.val)
+
+    swap(w)
+    print(w.val)
+    print(w.next.val)
+    print(w.next.next.val)
+    print(w.next.next.next.val)
+
+def swap(x):
+
+    temp = x.val
+    temp2 = x.next.val
+    x.val = temp2
+    x.next.val = temp
+
+    if x.next.next== None:
+        return x
+    else:
+        swap(x.next.next)
+        return x
+
+main()
+