added product of elements in array except arr[i] newArrayWithProductOfOtherElements.py

Author: DIL8654

.gitignore

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+.idea/*

com/d3achannel/algorithms/newArrayWithProductOfOtherElements.py

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+import  time;
+from functools import reduce ;
+import numpy;
+X = [1,2,3,4,5];
+
+
+"""
+
+initial implementation with O(n^2)
+
+"""
+def calculateNewArray(x):
+    start = time.time();
+
+    n = [1 for _ in range(len(X))];
+    for i in range(len(x)):
+        for j in range(len(x)):
+            if i != j:
+                n[i] *= x[j];
+    end = time.time()
+    print("time for calculateNewArray in milliseconds ", (end - start)*1000);
+    return n;
+
+print(calculateNewArray(X));
+
+"""
+
+Optimized with Divition  and using numpy
+complexity is O(n)
+
+"""
+def calculateNewArray2(x):
+
+    start = time.time();
+
+    n = [1 for _ in range(len(x))];
+    sumvalue  = numpy.prod(x);
+
+    for i in range(len(x)):
+        n[i] = sumvalue/x[i];
+
+    end = time.time()
+    print("time for calculateNewArray2 in milliseconds ", (end - start) * 1000);
+
+    return n;
+
+print(calculateNewArray2(X));
+
+"""
+
+Optimized with Divition  and using reduce((lambda x, y: x * y), list1) 
+
+complexity is O(n)
+
+"""
+
+def calculateNewArray3(x):
+
+    start = time.time();
+
+    n = [1 for _ in range(len(x))];
+    sumvalue  = reduce((lambda x, y: x * y), x)
+
+    for i in range(len(x)):
+        n[i] = sumvalue/x[i];
+
+    end = time.time()
+    print("time for calculateNewArray3 in milliseconds ", (end - start) * 1000);
+
+    return n;
+
+print(calculateNewArray3(X));