added permutations program

peter/permutations.py

@@ -0,0 +1,36 @@
+class Entry:
+    def __init__(self, frontArray, backArray) -> None:
+        self.frontArray = frontArray
+        self.backArray = backArray
+
+
+
+class Permu:
+    def __init__(self, array) -> None:
+        self.array = array
+        self.bucket = []
+
+    def print_all(self):
+        firstEntry = Entry([], self.array.copy())
+        self.bucket.append(firstEntry)
+
+        while len(self.bucket) > 0:
+            current = self.bucket.pop(0)
+            if len(current.backArray) == 0:
+                print(current.frontArray)
+            else:
+                for i in range(len(current.backArray)):
+                    newEntry = Entry(current.frontArray.copy(), current.backArray.copy())
+                    newEntry.frontArray.append(current.backArray[i])
+                    newEntry.backArray.pop(i)
+                    self.bucket.append(newEntry)
+
+
+def basictest1():
+    inputString = input("give an array: ")
+    inputArray = inputString.split(" ")
+    permu = Permu(inputArray)
+    permu.print_all()
+
+if __name__ == "__main__":
+    basictest1()