Major rework to improve code quality and add automation checks (#805)

* delete secant method - it is identical to regula falsi

* document + improvize root finding algorithms

* attempt to document gaussian elimination

* added file brief

* commented doxygen-mainpage, added files-list link

* corrected files list link path

* files-list link correction - this time works :)

* document successive approximations

* cleaner equation

* updating DIRECTORY.md

* documented kmp string search

* document brute force string search

* document rabin-karp string search

* fixed mainpage readme

* doxygen v1.8.18 will suppress out the #minipage in the markdown

* cpplint correction for header guard style

* github action to auto format source code per cpplint standard

* updated setting to add 1 space before `private` and `public` keywords

* auto rename files and auto format code

* added missing "run" for step

* corrected asignmemt operation

* fixed trim and assign syntax

* added git move for renaming bad filenames

* added missing pipe for trim

* added missing space

* use old and new fnames

* store old fname using echo

* move files only if there is a change in filename

* put old filenames in quotes

* use double quote for old filename

* escape double quotes

* remove old_fname

* try escape characters and echo"

* add file-type to find

* cleanup echo

* ensure all trim variables are also in quotes

* try escape -quote again

* remove second escpe quote

* use single quote for first check

* use carets instead of quotes

* put variables in brackets

* remove -e from echo

* add debug echos

* try print0 flag

* find command with while instead of for-loop

* find command using IFS instead

* 🎉 IFS fix worked - escaped quotes for git mv

* protetc each word in git mv ..

* filename exists in lower cases - renamed

* 🎉 git push enabled

* updating DIRECTORY.md

* git pull & then push

* formatting filenames d7af6fdc8c

* formatting source-code for d7af6fdc8c

* remove allman break before braces

* updating DIRECTORY.md

* added missing comma lost in previous commit

* orchestrate all workflows

* fix yml indentation

* force push format changes, add title to DIRECTORY.md

* pull before proceeding

* reorganize pull commands

* use master branches for actions

* rename .cc files to .cpp

* added class destructor to clean up dynamic memory allocation

* rename to awesome workflow

* commented whole repo cpplint - added modified files lint check

* removed need for cpplint

* attempt to use actions/checkout@master

* temporary: no dependency on cpplint

* formatting filenames 153fb7b8a5

* formatting source-code for 153fb7b8a5

* updating DIRECTORY.md

* fix diff filename

* added comments to the code

* added test case

* formatting source-code for a850308fba

* updating DIRECTORY.md

* added machine learning folder

* added adaline algorithm

* updating DIRECTORY.md

* fixed issue [LWG2192](https://cplusplus.github.io/LWG/issue2192) for std::abs on MacOS

* add cmath for same bug: [LWG2192](https://cplusplus.github.io/LWG/issue2192) for std::abs on MacOS

* formatting source-code for f8925e4822

* use STL's inner_product

* formatting source-code for f94a330594

* added range comments

* define activation function

* use equal initial weights

* change test2 function to predict

* activation function not friend

* previous commit correction

* added option for predict function to return value before applying activation function as optional argument

* added test case to classify points lying within a sphere

* improve documentation for adaline

* formatting source-code for 15ec4c3aba

* added cmake to geometry folder

* added algorithm include for std::max

* add namespace - machine_learning

* add namespace - statistics

* add namespace - sorting

* added sorting algos to namespace sorting

* added namespace string_search

* formatting source-code for fd69530515

* added documentation to string_search namespace

* feat: Add BFS and DFS algorithms to check for cycle in a directed graph

* Remove const references for input of simple types

Reason: overhead on access

* fix bad code

sorry for force push

* Use pointer instead of the non-const reference

because apparently google says so.

* Remove a useless and possibly bad Graph constuctor overload

* Explicitely specify type of vector during graph instantiation

* updating DIRECTORY.md

* find openMP before adding subdirectories

* added kohonen self organizing map

* updating DIRECTORY.md

* remove older files and folders from gh-pages before adding new files

* remove chronos library due to inacceptability by cpplint

* use c++ specific static_cast instead

* initialize radom number generator

* updated image links with those from CPP repository

* rename computer.... folder to numerical methods

* added durand kerner method for root computation for arbitrarily large polynomials

* fixed additional comma

* fix cpplint errors

* updating DIRECTORY.md

* convert to function module

* update documentation

* move openmp to main loop

* added two test cases

* use INT16_MAX

* remove return statement from omp-for loop and use "break"

* run tests when no input is provided and skip tests when input polynomial is provided

* while loop cannot have break - replaced with continue and check is present in the main while condition

* (1) break while loop (2) skip runs on break_loop instead of hard-break

* add documentation images

* use long double for errors and tolerance checks

* make iterator variable i local to threads

* add critical secions to omp threads

* bugfix: move file writing outside of the parallel loop
othersie, there is no gurantee of the order of roots written to file

* rename folder to data_structures

* updating DIRECTORY.md

* fix ambiguous symbol `size`

* add data_structures to cmake

* docs: enable tree view, add timestamp in footer, try clang assistaed parsing

* doxygen - open links in external window

* remove invalid parameter from function docs

* use HTML5 img tag to resize images

* move file to proper folder

* fix documentations and cpplint

* formatting source-code for aacaf9828c

* updating DIRECTORY.md

* cpplint: add braces for multiple statement if

* add explicit link to badges

* remove  duplicate line

Signed-off-by: Krishna Vedala <7001608+kvedala@users.noreply.github.com>

* remove namespace indentation

* remove file associations in settings

* add author name

* enable cmake in subfolders of data_structures

* create and link object file

* cpp lint fixes and instantiate template classes

* cpp lint fixes and instantiate template classes

Signed-off-by: Krishna Vedala <7001608+kvedala@users.noreply.github.com>

* cpplint - ignore `build/include`

Signed-off-by: Krishna Vedala <7001608+kvedala@users.noreply.github.com>

* disable redundant gcc compilation in cpplint workflow

Signed-off-by: Krishna Vedala <7001608+kvedala@users.noreply.github.com>

* template header files contain function codes as well and removed redundant subfolders

Signed-off-by: Krishna Vedala <7001608+kvedala@users.noreply.github.com>

* updating DIRECTORY.md

* remove semicolons after functions in a class

Signed-off-by: Krishna Vedala <7001608+kvedala@users.noreply.github.com>

* cpplint header guard style

Signed-off-by: Krishna Vedala <7001608+kvedala@users.noreply.github.com>

* remove semilon

Signed-off-by: Krishna Vedala <7001608+kvedala@users.noreply.github.com>

* added LU decomposition algorithm

Signed-off-by: Krishna Vedala <7001608+kvedala@users.noreply.github.com>

* added QR decomposition algorithm

Signed-off-by: Krishna Vedala <7001608+kvedala@users.noreply.github.com>

* use QR decomposition to find eigen values

Signed-off-by: Krishna Vedala <7001608+kvedala@users.noreply.github.com>

* updating DIRECTORY.md

* use std::rand for thread safety

Signed-off-by: Krishna Vedala <7001608+kvedala@users.noreply.github.com>

* move srand to main()

Signed-off-by: Krishna Vedala <7001608+kvedala@users.noreply.github.com>

* cpplint braces correction

Signed-off-by: Krishna Vedala <7001608+kvedala@users.noreply.github.com>

* updated eigen value documentation

Signed-off-by: Krishna Vedala <7001608+kvedala@users.noreply.github.com>

* fix matrix shift doc

Signed-off-by: Krishna Vedala <7001608+kvedala@users.noreply.github.com>

* rename CONTRIBUTION.md to CONTRIBUTING.md #836

* remove 'sort alphabetical order' check

* added documentation check

* remove extra paranthesis

* added gitpod

* added gitpod link from README

* attempt to add vscode gitpod extensions

* update gitpod extensions

* add gitpod extensions cmake-tools and git-graph

* remove gitpod init and add commands

* use init to one time install doxygen, graphviz, cpplint

* use gitpod dockerfile

* add ninja build system to docker

* remove configure task

* add github prebuild specs to gitpod

* disable gitpod addcommit

* update documentation for kohonen_som

* added ode solve using forward euler method

* added mid-point euler ode solver

* fixed itegration step equation

* added semi-implicit euler ODE solver

* updating DIRECTORY.md

* fix cpplint issues - lines 117 and 124

* added documentation to ode group

* corrected semi-implicit euler function

* updated docs and test cases better structure

* replace `free` with `delete` operator

* formatting source-code for f55ab50cf2

* updating DIRECTORY.md

* main function must return

* added machine learning group

* added kohonen som topology algorithm

* fix graph image path

* updating DIRECTORY.md

* fix braces

* use snprintf instead of sprintf

* use static_cast

* hardcode character buffer size

* fix machine learning groups in documentation

* fix missing namespace function

* replace kvedala fork references to TheAlgorithms

* fix bug in counting_sort

Co-authored-by: github-actions <${GITHUB_ACTOR}@users.noreply.github.com>
Co-authored-by: Anmol3299 <mittalanmol22@gmail.com>

search/hash_search.cpp

@@ -1,100 +1,139 @@
-// Copyright 2020 Arctic2333
-#include <stdlib.h>
-#include<stdio.h>
-#define MAX 6  // Determines how much data
-# define HASHMAX 5  // Determines the length of the hash table
 /**
-  * Hash Search Algorithm
-  * Best Time Complexity Ω(1)
-  * In this algorithm, we use the method of division and reservation remainder to construct the hash function, 
-  * and use the method of chain address to solve the conflict, that is, we link a chain list after the data, 
-  * and store all the records whose keywords are synonyms in the same linear chain list. */
-int data[MAX] = { 1, 10, 15, 5, 8, 7};  // test data
+ * \file
+ * \brief Hash Search Algorithm - Best Time Complexity Ω(1)
+ *
+ * \copyright 2020 Arctic2333
+ *
+ * In this algorithm, we use the method of division and reservation remainder to
+ * construct the hash function, and use the method of chain address to solve the
+ * conflict, that is, we link a chain list after the data, and store all the
+ * records whose keywords are synonyms in the same linear chain list.
+ *
+ * @warning This program is only for educational purposes. It has serious flaws
+ * in implementation with regards to memory management resulting in large
+ * amounts of memory leaks.
+ * @todo fix the program for memory leaks and better structure in C++ and not C
+ * fashion
+ */
+#include <cstdlib>
+#include <iostream>
+
+#define MAX 6      ///< Determines how much data
+#define HASHMAX 5  ///< Determines the length of the hash table
+
+int data[MAX] = {1, 10, 15, 5, 8, 7};  //!< test data
+
+/**
+ * a one-way linked list
+ */
 typedef struct list {
-    int key;
-    struct list * next;
-}
-node, * link;
-node hashtab[HASHMAX];
-int counter = 1;
-/* int h(int key)
+    int key;            //!< key value for node
+    struct list* next;  //!< pointer to next link in the chain
+} node,                 /**< define node as one item list */
+    *link;              ///< pointer to nodes
+
+node hashtab[HASHMAX];  ///< array of nodes
+
+// int counter = 1;
+
+/**
  * Mode of hash detection :
- * Division method */
-int h(int key) {
-    return key % HASHMAX;
-}
-/* void create_list(int key)
+ * Division method
+ * \param [in] key to hash
+ * \returns hash value for `key`
+ */
+int h(int key) { return key % HASHMAX; }
+
+/**
  * The same after the remainder will be added after the same hash header
  * To avoid conflict, zipper method is used
- * Insert elements into the linked list in the header */
+ * Insert elements into the linked list in the header
+ * \param [in] key key to add to list
+ * \warning dynamic memory allocated to `n` never gets freed.
+ * \todo fix memory leak
+ */
 void create_list(int key) {  // Construct hash table
     link p, n;
     int index;
-    n = (link) malloc(sizeof(node));
-    n -> key = key;
-    n -> next = NULL;
+    n = (link)malloc(sizeof(node));
+    n->key = key;
+    n->next = NULL;
     index = h(key);
     p = hashtab[index].next;
     if (p != NULL) {
-        n -> next = p;
+        n->next = p;
         hashtab[index].next = n;
     } else {
-        hashtab[index].next = n; }
+        hashtab[index].next = n;
+    }
 }
-/* int hash_search(int key)
- * Input the key to be searched, and get the hash header position through the H (int key) function,
- * then one-dimensional linear search.
- * If found @return element depth and number of searches
- * If not found @return -1 */
-int hash_search(int key) {  // Hash lookup function
+
+/**
+ * Input the key to be searched, and get the hash header position through the H
+ * (int key) function, then one-dimensional linear search. If found @return
+ * element depth and number of searches If not found @return -1
+ */
+int hash_search(int key, int* counter) {  // Hash lookup function
     link pointer;
     int index;
-    counter = 0;
+
+    *counter = 0;
     index = h(key);
     pointer = hashtab[index].next;
-    printf("data[%d]:", index);
+
+    std::cout << "data[" << index << "]:";
+
     while (pointer != NULL) {
-        counter++;
-        printf("data[%d]:", pointer -> key);
-        if (pointer -> key == key)
+        counter[0]++;
+        std::cout << "data[" << pointer->key << "]:";
+        if (pointer->key == key)
             return 1;
         else
-            pointer = pointer -> next;
+            pointer = pointer->next;
     }
+
     return 0;
 }
+
+/** main function */
 int main() {
     link p;
-    int key, index, i;  // Key is the value to be found
+    int key, index, i, counter;  // Key is the value to be found
     index = 0;
+
     // You can write the input mode here
     while (index < MAX) {  // Construct hash table
         create_list(data[index]);
         index++;
     }
+
     for (i = 0; i < HASHMAX; i++) {  // Output hash table
-        printf("hashtab [%d]", i);
-        printf("\n");
+        std::cout << "hashtab [" << i << "]\n";
+
         p = hashtab[i].next;
+
         while (p != NULL) {
-            printf("please int key:");
-            if (p -> key > 0)
-                printf("[%d]", p -> key);
-            p = p -> next;
+            std::cout << "please int key:";
+            if (p->key > 0)
+                std::cout << "[" << p->key << "]";
+            p = p->next;
         }
-        printf("\n");
+        std::cout << std::endl;
     }
+
     while (key != -1) {
         // You can write the input mode here
         // test key = 10
         key = 10;
-        if (hash_search(key))
-            printf("search time = %d\n", counter);
+        if (hash_search(key, &counter))
+            std::cout << "search time = " << counter << std::endl;
         else
-            printf("no found!\n");
+            std::cout << "no found!\n";
         key = -1;  // Exit test
-        /* The test sample is returned as: data[0]:data[5]:data[15]:data[10]:search time = 3
-         * The search is successful. There are 10 in this set of data */
+        /* The test sample is returned as:
+         * data[0]:data[5]:data[15]:data[10]:search time = 3 The search is
+         * successful. There are 10 in this set of data */
     }
+
     return 0;
 }