Add day 12

Author: MadhavBahl

README.md

@@ -28,10 +28,10 @@ Read [CONTRIBUTING.md](./CONTRIBUTING.md) for contribution guidelines.
 9. [Day 9 -- Smallest Substring Problem](./day9/) -- [http://codetoexpress.tech/dc/day9/](http://codetoexpress.tech/dc/day9/)
 10. [Day 10 -- String Permutation Problem](./day10/) -- [http://codetoexpress.tech/dc/day10/](http://codetoexpress.tech/dc/day10/)
 11. [Day 11 -- Longest Common Substring](./day11/) -- [http://codetoexpress.tech/dc/day11/](http://codetoexpress.tech/dc/day11/)
+11. [Day 12 -- Substring Search Algorithms](./day12/) -- [http://codetoexpress.tech/dc/day12/](http://codetoexpress.tech/dc/day12/)
 
 ## Timeline
 
 <p align="center">
   <img src="./timeline.png" alt="timeline">
-</p>
-
+</p>

day11/ques.png

@@ -0,0 +1 @@
+// To Be Added

day12/JavaScript/KMP.js

@@ -0,0 +1 @@
+// To Be Added

day12/JavaScript/ZAlgorithm.js

@@ -0,0 +1 @@
+// To Be Added

day12/JavaScript/boyer_moore.js

@@ -0,0 +1 @@
+// To Be Added

day12/JavaScript/rabin_karp.js

@@ -0,0 +1,34 @@
+/**
+ * @author MadhavBahlMD
+ * @date 04/01/2018
+ * In this case, the worst case Time Complexity will be O(m.n), 
+ * m and n are the lengths of string and pattern respectively.
+ */
+
+function substringSearch (str, pattern) {
+    let strLen = str.length,
+        patLen = pattern.length,
+        flag = 0;
+
+    for (let i=0; i<(strLen-patLen+1); i++) {
+        if (str[i] === pattern[0]) {
+            flag = 1;
+            for (let j=1; j<patLen; j++) {
+                if (str[i+j] !== pattern[j]) {
+                    flag = 0;
+                    break;
+                }
+            }
+            if (flag === 1) {
+                console.log (i);
+                return i;
+            } 
+        }
+    }
+
+    console.log (-1);
+    return -1;
+}
+
+substringSearch ("helloworld", "world");
+substringSearch ("abcrxyzgf", "xyz");

day12/JavaScript/sol.js

@@ -0,0 +1,122 @@
+![cover](./cover.png)
+
+# day 12 - Substring Search Problem 
+
+**Question** -- Given a text, and a pattern, find whether the given pattern exists in the text or not.
+
+**Implement various algorithms**
+
+```   
+    a) Brute Force Search
+    b) Knuth-Morris-Pratt Algorithm
+    c) Z Algorithm
+    d) Rabin Karp Algorithm
+    e) Boyer Moore Algorithm
+```
+
+### Example
+
+```
+input: text: helloworld, substring: hello
+output: 0 (index of 'h', where the substring starts)
+
+input: text: helloworld, substring: hop
+output: -1
+
+input: text: abcrxyzgf, substring: xyz
+output: 4
+```
+
+![ques](./ques.png)
+
+## A) Brute Force Search
+
+### JavaScript Implementation
+
+#### [Solution](./JavaScript/sol.js)
+
+Substring search can be done using brute force. 
+In this case, the worst case Time Complexity will be O(m.n), m and n are the lengths of string and pattern respectively.
+
+```js
+/**
+ * @author MadhavBahlMD
+ * @date 04/01/2018
+ * In this case, the worst case Time Complexity will be O(m.n), 
+ * m and n are the lengths of string and pattern respectively.
+ */
+
+function substringSearch (str, pattern) {
+    let strLen = str.length,
+        patLen = pattern.length,
+        flag = 0;
+
+    for (let i=0; i<(strLen-patLen+1); i++) {
+        if (str[i] === pattern[0]) {
+            flag = 1;
+            for (let j=1; j<patLen; j++) {
+                if (str[i+j] !== pattern[j]) {
+                    flag = 0;
+                    break;
+                }
+            }
+            if (flag === 1) {
+                console.log (i);
+                return i;
+            } 
+        }
+    }
+
+    console.log (-1);
+    return -1;
+}
+
+substringSearch ("helloworld", "world");
+substringSearch ("abcrxyzgf", "xyz");
+```
+
+## B) Knuth-Morris-Pratt Algorithm
+
+### JavaScript Implementation
+
+#### [Solution](./JavaScript/KMP.js)
+
+```js
+To Be Added
+```
+
+##  C) Z Algorithm
+
+### JavaScript Implementation
+
+#### [Solution](./JavaScript/ZAlgorithm.js)
+
+```js
+To Be Added
+```
+
+## D) Rabin Karp Algorithm
+
+### JavaScript Implementation
+
+#### [Solution](./JavaScript/rabin_karp.js)
+
+```js
+To Be Added
+```
+
+## E) Boyer Moore Algorithm
+
+### JavaScript Implementation
+
+#### [Solution](./JavaScript/boyer_moore.js)
+
+```js
+To Be Added
+```
+
+### Have Another solution?
+
+The beauty of programming lies in the fact that there is never a single solution to any problem.
+
+In case you have an alternative way to solve this problem, do contribute to this repository (https://github.com/CodeToExpress/dailycodebase)

day12/README.md

@@ -615,4 +615,4 @@ main
 
 The beauty of programming lies in the fact that there is never a single solution to any problem.
 
-In case you have an alternative way to solve this problem, do contribute to this repository (https://github.com/CodeToExpress/dailycodebase) :)
+In case you have an alternative way to solve this problem, do contribute to this repository (https://github.com/CodeToExpress/dailycodebase)