CodeReportSolutions

Code Report Solutions

Following are some simple solutions to videos found on YouTube. Idea is to make it easier for comparing and learning z^3 and other beautiful languages.

Number of Different Integers in a String

Video: https://www.youtube.com/watch?v=59vAjBS3yZM [APL Wins (vs C++, Java & Python)]

z^3 Solution

s="ad3343sadfsd343434df343443sff";
(s#/[^\d]+/)∪

Result: 3343 343434 343443

1. splits string using the postfix regexp pattern. ∪ extracts unique from the results

// 12 Character z^3 Solution vs. 14 Character APL Solution

Final Value of Variable After Performing Operations

Video: https://www.youtube.com/watch?v=8Njxgy4itts [4 APL Solutions in 10 Minutes!]

z^3 Solution

m=["--x","x++","x++"].print(); [0]@(m!)

// m! makes this to a function which is evaluated using [0]@. 0 forms a single input combinatorial argument. // [0..10]@(m!) can be used to loop through a set of initial values

Count Negative Numbers in a Sorted Matrix

Video: https://www.youtube.com/watch?v=pDbDtGn1PXk [LeetCode 176 Problem 1 - Count Negative Numbers in a Sorted Matrix]

z^3 Solution

x=[-2,-1,0;-1,1,3;-1,2,4];
(x⍌).findv(NEGATIVE)#

Gives answer 4

// ⍌ Flatten Array // .findv Gives result of function call NEGATIVE // # Counts the result // Also note simpler z^3 Array Notation used to create the variable x (with , and ;). Usual Javascript array notations also work.

Check if a matrix is an X-Matrix (X like diagonals are filled)

Video: https://www.youtube.com/watch?v=8ynsN4nJxzU [APL vs BQN vs J vs Q vs NumPy vs Julia vs R - A comparison of seven different programming languages across a few different language criteria.]

z^3 Solution

m=[2 0 0 1; 0 3 1 0; 0 5 2 0; 4 0 0 2];
n=(m#)[0];
xm=|n| |+| |n|.reverse();
xm|==|(m.$("x!=0?1:0"!))

Gives answer true

// m# gives length of array m. |n| gives n dimensional Identity Matrix, which is added using |+| to the .reverse() of same array. // |==| is used to compare this to the m, .$ is used to apply the function "x!=0?1:0"! to every element. "x!=0?1:0"! shows how a function can be created from a string with the ! operator. // Also note simpler z^3 Array Notation used to create the variable x (with , (when positive numbers alone are used, the comma is also optional) and ;). Usual Javascript array notations also work.