Neet Code Problems - Revision history

Joseph: /* z^3 Solution */

2025-06-01T02:41:38Z

z^3 Solution

2025-06-01T02:40:11Z

z^3 Solution

2024-09-12T17:23:59Z

2024-09-12T16:54:16Z

Duplicate Integer

2024-09-12T04:55:36Z

Problems and Solutions

2024-09-12T04:55:08Z

Products of Array Discluding Self

2024-09-12T04:52:41Z

z^3 Solution

2024-09-12T04:49:13Z

Powerful Solution to Indexing Problem (1 character in z^3 vs 3 in APL)

2024-09-12T04:36:13Z

z^3 Solution

2024-09-12T04:35:20Z

z^3 Solution

@@ Line 78: / Line 78: @@
 nx.$$(PRODUCT)
 </pre>
 Gives answer:

@@ Line 52: / Line 52: @@
 <pre>
 n=[1,2,4,6];
-n⪥n≡∏
+nx=n⪥ (0..(n.length-1));
 </pre>
 Gives answer
-{| style="" id="TABLE23" class="null wikitable" donotcaption="true" |
 |-
-| 24
+| 48
 |-
-|12
+| 24
 |-
-|48
+| 12
 |-
-|24
+| 8
 |}
 <pre>
 n=[-1,1,0,-3,3];
-n⪥n≡∏
+nx=n⪥ (0..(n.length-1));
 </pre>
@@ Line 80: / Line 82: @@
-{| style="" id="TABLE24" class="null wikitable" donotcaption="true" |
 |-
 | 0
 |-
-| 0
+| style="cursor: col-resize;" | 0
 |-
-| 0
+| 9
 |-
@@ Line 98: / Line 101: @@
 |}
 Notes:
@@ Line 104: / Line 108: @@
 n⪥n can be written as n.around(n) also.
 ==Duplicate Integer==

@@ Line 169: / Line 169: @@
 #1n extracts all elements from column 1 (note use of 1n for column n)
 >1 Checking if the product is greater than 1
 =Other Interesting Solutions=

← Older revision		Revision as of 16:54, 12 September 2024
Line 158:		Line 158:

	This approach checks for lengths greater than 1 byrow, and cumuluate with OR over the entire array.		This approach checks for lengths greater than 1 byrow, and cumuluate with OR over the entire array.
		+
		+	Another solution:
		+	n=[1,2,3,1];
		+	∏((n⍣)#1n)>1
		+
		+	Answer: true
		+
		+	∏ Product
		+	n⍣ gives FREQUENCY of each element of n
		+	#1n extracts all elements from column 1 (note use of 1n for column n)
		+	>1 Checking if the product is greater than 1

	=Other Interesting Solutions=		=Other Interesting Solutions=

@@ Line 21: / Line 21: @@
-==Powerful Solution to Indexing Problem (1 character in z^3 vs 3 in APL)==
+==Product of Array Except Self==
-Video: https://www.youtube.com/watch?v=ctbGMuakpHk [Product of Array Except Self - Leetcode 238 - Python]
+Video: https://www.youtube.com/watch?v=bNvIQI2wAjk [Product of Array Except Self - Leetcode 238 - Python]
 Problem Description:

← Older revision		Revision as of 04:55, 12 September 2024
Line 20:		Line 20:
	=Problems and Solutions=		=Problems and Solutions=

−
−	~~==Products of Array Discluding Self==~~
−
−	~~Video: https://www.youtube.com/watch?v=bNvIQI2wAjk [I ❤ APL and Haskell #2 ]~~
−
−	~~===z^3 Solution===~~
−	~~<pre>~~
−	~~a=[-1,-2,-3,4,3,2,1];~~
−	~~∏±a~~
−	~~</pre>~~
−
−	~~Gives answer -1~~
−
−	∏ is Product, ± is SIGN function. APL has 3 characters it its solution (selected as the best solution in the video because of its brevity). Interesting that the solution with z^3 has even less characters, just 2.

	==Powerful Solution to Indexing Problem (1 character in z^3 vs 3 in APL)==		==Powerful Solution to Indexing Problem (1 character in z^3 vs 3 in APL)==

@@ Line 165: / Line 165: @@
 x=>n⒤x Function x, defined as n find indices that contain x
 ≡ can be used to loop to check greater than 1 etc
 =Other Interesting Solutions=

← Older revision		Revision as of 04:49, 12 September 2024
Line 118:		Line 118:

	n⪥n can be written as n.around(n) also.		n⪥n can be written as n.around(n) also.
		+
		+
		+	==Duplicate Integer==
		+
		+	Video: https://www.youtube.com/watch?v=3OamzN90kPg [Contains Duplicate - Leetcode 217 - Python]
		+
		+	Problem Description:
		+
		+	Given an integer array nums, return true if any value appears more than once in the array, otherwise return false.
		+
		+	Example 1:
		+
		+	Input: nums = [1, 2, 3, 3]
		+
		+	Output: true
		+	Example 2:
		+
		+	Input: nums = [1, 2, 3, 4]
		+
		+	Output: false
		+
		+	===z^3 Solution===
		+	<pre>
		+	n=[1,2,3,1];
		+	(n∪).$(x=>n⒤x)
		+	</pre>
		+
		+	Gives answer
		+
		+	{\| style="" id="TABLE2" class="null wikitable" donotcaption="true" \|
		+	\|-
		+	\| 0
		+	\| 3
		+
		+	\|-
		+	\| 1
		+
		+	\|-
		+	\| 2
		+
		+
		+	\|}
		+	Notes:
		+	n∪ Uniques of n array
		+	.$ Apply function to each element
		+	x=>n⒤x Function x, defined as n find indices that contain x
		+	≡ can be used to loop to check greater than 1 etc

	=Other Interesting Solutions=		=Other Interesting Solutions=

@@ Line 113: / Line 113: @@
 |}
 ⪥ is the .around operator on an array, which takes one or more indices from the second argument to give you an array except that index.
 ≡∏ Product (∏) conducted by row (≡)
 =Other Interesting Solutions=

@@ Line 72: / Line 72: @@
 {| style="" id="TABLE23" class="null wikitable" donotcaption="true" |
 |-
-| style="cursor: row-resize;" 24
+| 24
 |-
-| style="cursor: auto;" 12
+|12
 |-
-| style="cursor: auto;" 48
+|48
 |-
-| style="cursor: auto;" 24
+|24
@@ Line 91: / Line 91: @@
 </pre>
-Gives answe:
+Gives answer: