m

.deepsource.toml

@@ -0,0 +1,22 @@
+version = 1
+
+[[analyzers]]
+name = "python"
+enabled = true
+
+  [analyzers.meta]
+  runtime_version = "3.x.x"
+
+[[analyzers]]
+name = "go"
+enabled = true
+
+  [analyzers.meta]
+  import_paths = ["github.com/TesseractCoding/NeoAlgo"]
+
+[[analyzers]]
+name = "javascript"
+enabled = true
+
+  [analyzers.meta]
+  environment = ["nodejs"]

C-Plus-Plus/README.md

@@ -43,6 +43,8 @@
 - [Z Algorithm](cp/zalgorithm.cpp)
 - [ArraySub](cp/ARRAYSUB.cpp)
 - [Suduko Solver](cp/SudukoSolver.cpp)
+- [Josephus Problem](cp/Josephus.cpp)
+- [NQueens](cp/NQueens.cpp)
 - [Longest Subarray with Zero Sum](cp/ZeroSum.cpp)
 - [Next Largest Permutation](cp/NextPermutation.cpp)
 
@@ -83,9 +85,13 @@
 - [Post-order (LRN) Tree Traversal](graphs/Postorder_Traversal.cpp)
 - [Pre-order (NLR) Tree Traversal](/graphs/Preorder_Traversal.cpp)
 - [Prim's Algorithm](graphs/Prim_Algorithm.cpp)
+- [Depth First Search Algorithm](graphs/DFS.cpp)
 - [Cycle Detection in Graph](graphs/detect_cycle.cpp)
+- [Cycle Detection in a Directed Graph](graphs/DirectedCycleDetection.cpp)
 - [Check for bipartite graph](graphs/Check_for_bipartite_graph.cpp)
 - [Toplogical Sort in Diredted Acyclic Graph (DAG)](graphs/TopologicalSort.cpp)
+- [Detect Negative Cycle in Graph](graphs/DetectNegativeCycle.cpp)
+- [Bellman Ford's Algorithm](graphs/BellmanFord.cpp)
 
 ## Searching
 
@@ -116,6 +122,8 @@
 ## Stack based problems
 
 - [Largest rectangular area under histogram](stack/Largest_rect_area_under_histogram.cpp)
+- [Check for balanced parenthesis](stack/Check_for_balanced_parenthesis.cpp)
+- [Stock Span Problem](stack/Stock_span_problem.cpp)
 
 ## Machine Learning
 
@@ -150,6 +158,8 @@ _add list here_
 - [Implement Floyd-Warshall Algorithm](dp/floyd_warshall.cpp)
 - [Maximum Subarray Sum](dp/Max_subarray_sum(DP).cpp)
 - [Rectangle Cutting Problem](dp/Rectangle_cutting.cpp)
+- [Partition Problem](dp/Partition_Problem.cpp)
+- [Egg Dropping Problem](dp/Egg_Dropping.cpp)
 - [Wild Card Pattern Matching](dp/WildCardMatching.cpp)
 - [Matrix Chain Multiplication](dp/Matrix_Chain_Multiplication.cpp)
 - [Zero One Knapsack](dp/Zero_One_Knapsack.cpp)
@@ -162,6 +172,7 @@ _add list here_
 
 - [Affine substitution Cipher](cryptography/Affine_substitution_Cipher.cpp)
 - [Vigenere Cipher](cryptography/Vigenere_Cipher.cpp)
+- [Vernam Cipher](cryptography/VernamCipher.cpp)
 
 ## Computational Geometry
 
@@ -184,5 +195,4 @@ _add list here_
 - [Least Common Multiple](other/lcm.cpp)
 - [Kth largest element](other/Kth_largest_element.cpp.cpp)
 - [Kth smallest element](other/Kth_smallest_element.cpp)
-- [Generate all Subsets](other/subsets.cpp)
-- [Stock Span Problem](other/Stock_span_problem.cpp)
+- [Generate all Subsets](other/subsets.cpp)

C-Plus-Plus/cp/Josephus.cpp

@@ -0,0 +1,34 @@
+/**
+Josephus problem is a famous problem.
+In each iteration we kill the every kth
+person in a circular arrangement of n persons.
+Find the person who is alive at the end.
+0-based indexing
+link to the problem : https://en.wikipedia.org/wiki/Josephus_problem
+**/
+
+#include <iostream>
+using namespace std;
+
+int solution(int n, int k) {
+	if (n == 1)
+		return 0;
+	return (k + solution(n - 1, k)) % n;
+}
+
+int main() {
+	int people, gap;
+	cin >> people >> gap;
+	cout << solution(people, gap) << '\n';
+	return 0;
+}
+
+/**
+Input :
+4 2
+Output :
+0
+
+Time Complexity : O(n)
+Space Complexity : O(1)
+**/

C-Plus-Plus/cp/NQueens.cpp

@@ -0,0 +1,71 @@
+/**
+N-Queens problem is a famous problem
+The paradigm used to solve the problem is backtracking
+The problem is to find a way to place n queens on nXn board
+such that no queen can kill the other
+**/
+
+#include <bits/stdc++.h>
+using namespace std;
+
+#define N 20
+
+void solve(bool board[N][N], bool cols[N], bool ndiag[2*N-1], bool rdiag[2*N-1], int row, string asf, int n) {
+
+    if(row == n) {
+        cout << asf << '.' << '\n';
+        return;
+    }
+
+    for(int col=0; col<n; col++) {
+        if(cols[col] == false && ndiag[row+col] == false && 
+            rdiag[row-col+n-1] == false) {
+                // place the queen
+                cols[col] = true;
+                ndiag[row+col] = true;
+                rdiag[row-col+n-1] = true;
+                board[row][col] = true;
+                solve(board, cols, ndiag, rdiag, row+1, asf+to_string(row)+"-"+to_string(col)+", ", n);
+                // backtrack
+                cols[col] = false;
+                ndiag[row+col] = false;
+                rdiag[row-col+n-1] = false;
+                board[row][col] = false;
+            }
+    }
+}
+
+int main() {
+	int n;
+	cin >> n;
+
+	bool board[N][N];
+    bool cols[N];
+    bool ndiag[2*N-1], rdiag[2*N-1];
+
+	// initialize
+	for(int i = 0; i < n; i++)
+		for(int j = 0; j < n; j++)
+			board[i][j] = false;
+
+    // initialize that no column has a queen
+	for(int i = 0; i < n; i++)
+		cols[i] = false;
+
+	for(int i = 0; i < 2*n-1; i++) {
+		ndiag[i] = false;
+		rdiag[i] = false;
+	}
+
+	solve(board, cols, ndiag, rdiag, 0, "", n);
+}
+
+/**
+Input :
+4
+Output :
+0-1, 1-3, 2-0, 3-2, .
+0-2, 1-0, 2-3, 3-1, .
+Space Complexity : O(n^2)
+Time Complexity : upperbounded by O(n^n)
+**/

C-Plus-Plus/cryptography/Caeser_Cipher.cpp

@@ -0,0 +1,47 @@
+#include<bits/stdc++.h>
+using namespace std;
+
+/* Encrypts the plain text message into a cipher 
+text by simply replacing each letter of a given 
+text by a letter '3' places down the alphabet. */
+string encode(string plain) {
+
+	string encrypt = "";
+	int length = plain.length();
+	for(int i = 0;i < length; ++i) {
+		if(plain[i] <= 91) {
+			//uppercase letter
+			encrypt += char((plain[i] - 65 + 3)%26 + 65);
+		} else if(plain[i] > 97) {
+			//lowercase letter
+			encrypt += char((plain[i] - 97 + 3)%26 + 97);
+		}
+	}
+
+	return encrypt;
+}
+
+int main() {
+
+	string plain,encrypt;
+	cout<<"Enter the plain text: ";
+	cin>>plain;
+
+	encrypt = encode(plain);
+	cout<<"Cipher Text: "<<encrypt<<endl;
+
+}
+
+/*
+Example:
+Text : TESSERACTCODING
+Shift: 3
+Cipher: WHVVHUDFWFRGLQJ
+
+Text : NEOALGO
+Shift: 3
+Cipher: QHRDOJR
+
+Time Complexity: O(n)
+Space Complexity: O(n)
+*/

C-Plus-Plus/cryptography/Homophonic_Cipher.cpp

@@ -0,0 +1,92 @@
+#include<bits/stdc++.h>
+using namespace std;
+
+//Mapping one plain-text alphabet to more than one cipher-text alphabet.
+void mapping(vector<vector<char> > &code) {    
+	code[0].push_back('Q');code[0].push_back('4');
+	code[1].push_back('W');
+	code[2].push_back('E');
+	code[3].push_back('R');
+	code[4].push_back('T');code[4].push_back('5');code[4].push_back('9');code[4].push_back('0');
+	code[5].push_back('Y');
+	code[6].push_back('U');
+	code[7].push_back('I');
+	code[8].push_back('O');code[8].push_back('8');
+	code[9].push_back('P');
+	code[10].push_back('A');
+	code[11].push_back('S');
+	code[12].push_back('D');
+	code[13].push_back('F');code[13].push_back('7');
+	code[14].push_back('G');code[14].push_back('2');
+	code[15].push_back('H');
+	code[16].push_back('J');
+	code[17].push_back('K');
+	code[18].push_back('L');code[18].push_back('1');
+	code[19].push_back('Z');code[19].push_back('6');
+	code[20].push_back('X');
+	code[21].push_back('C');
+	code[22].push_back('V');
+	code[23].push_back('B');
+	code[24].push_back('N');
+	code[25].push_back('M');	
+}
+
+/* Encodes characters of plain text by one of the 
+several different cipher text letters using a map. */
+string encode(string plain) {
+
+	vector<vector<char> >code(26);
+	mapping(code);
+	string encrypted = "";
+	int n = plain.length();
+	for(int i = 0;i < n; ++i) {
+		//if lowercase character
+		if(plain[i] >= 97) {
+			int num = (rand() % (code[plain[i] - 97].size()));
+
+			if(code[plain[i]-97][num] >= 65)
+				encrypted = encrypted+char(code[plain[i]-97][num]- 65 + 97);
+			else
+				encrypted = encrypted+code[plain[i]-97][num];
+		}
+		//uppercase letter
+		else {
+			int num = (rand() % (code[plain[i]-65].size()));
+			encrypted = encrypted+code[plain[i]-65][num];
+		}
+	}
+
+	return encrypted;
+}
+
+int main(){
+
+	vector<vector<char> >code(26);
+	mapping(code);
+
+	string plain,encrypt;
+	cout<<"Enter the plain text: ";
+	cin>>plain;
+
+	encrypt = encode(plain);
+	cout<<"Cipher Text: "<<encrypt<<endl;
+
+}
+
+/* Mapping used: 
+A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
+Q W E R T Y U I O P A S D F G H J K L Z X C V B N M
+4       5       8         7 2       1 6            
+        9                                          
+        0                         
+
+Example:
+Plain Text : TESSERACTCODING
+Cipher Text: 60LL5KQEZE2R87U
+
+Plain Text : NeoAlgo
+Cipher Text: 70gQsug
+
+Time Complexity: O(n)
+Space Complexity: O(1)                  
+*/

C-Plus-Plus/cryptography/Modified_Caeser_Cipher.cpp

@@ -0,0 +1,51 @@
+#include<bits/stdc++.h>
+using namespace std;
+
+/* Encrypts the plain text message into a cipher text 
+by simply replacing each letter of a given text by 
+some places down the alphabet. */
+string encode(string plain, int shift) {
+
+	string encrypt = "";
+	int length = plain.length();
+	for(int i = 0;i < length; ++i) {
+		if(plain[i] <= 91) {
+			//uppercase letter
+			encrypt += char((plain[i] - 65 + shift)%26 + 65);
+		} else if(plain[i] > 97) {
+			//lowercase letter
+			encrypt += char((plain[i] - 97 + shift)%26 + 97);
+		}
+	}
+
+	return encrypt;
+}
+
+int main() {
+
+	string plain,encrypt;
+	int shift;
+	cout<<"Enter the plain text: ";
+	cin>>plain;
+
+	cout<<"Enter the integer key to shift: ";
+	cin>>shift;
+
+	encrypt = encode(plain,shift);
+	cout<<"Cipher Text: "<<encrypt<<endl;
+
+}
+
+/*
+Example:
+Text : TESSERACTCODING
+Shift: 4
+Cipher: XIWWIVEGXGSHMRK
+
+Text : NEOALGO
+Shift: 2
+Cipher: PGQCNIQ
+
+Time Complexity: O(n)
+Space Complexity: O(n)
+*/