From 1cd7387231bddf9a10efedeb29e7c6fad46cab18 Mon Sep 17 00:00:00 2001
From: Rishu Rajan <56962548+RishuRajan@users.noreply.github.com>
Date: Thu, 1 Oct 2020 18:02:18 +0530
Subject: [PATCH 1/3] Create BinaryExponentiation

---
 Mathematics_Algo/BinaryExponentiation | 31 +++++++++++++++++++++++++++
 1 file changed, 31 insertions(+)
 create mode 100644 Mathematics_Algo/BinaryExponentiation

diff --git a/Mathematics_Algo/BinaryExponentiation b/Mathematics_Algo/BinaryExponentiation
new file mode 100644
index 0000000..74077e4
--- /dev/null
+++ b/Mathematics_Algo/BinaryExponentiation
@@ -0,0 +1,31 @@
+//This ia a technnique to calculate (a^n) in O(logn) time complexity
+#include<bits/stdc++.h>
+using namespace std;
+int power(int base,int num)
+{
+   int result=1;
+   while(num>0)
+   {
+     if(num%2)
+     {
+       result=result*base;
+       num--;
+     }
+     else
+     {
+       base=base*base;
+       num=num/2;
+     }
+  }
+  return result;
+}
+int main()
+{
+  int b,n,r;
+  cout<<"Enter Base And Power:";
+  cin>>b>>n;
+  power(b,n);
+  r=power(b,n);
+  cout<<r;
+  return 0;
+}

From 9eb4fd74468c0687ddbeea111e259e0482d85793 Mon Sep 17 00:00:00 2001
From: Rishu Rajan <56962548+RishuRajan@users.noreply.github.com>
Date: Thu, 1 Oct 2020 18:13:18 +0530
Subject: [PATCH 2/3] Create ModularExponentiation

---
 Mathematics_Algo/ModularExponentiation | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)
 create mode 100644 Mathematics_Algo/ModularExponentiation

diff --git a/Mathematics_Algo/ModularExponentiation b/Mathematics_Algo/ModularExponentiation
new file mode 100644
index 0000000..10a2f0c
--- /dev/null
+++ b/Mathematics_Algo/ModularExponentiation
@@ -0,0 +1,21 @@
+//It is a technique to calculate (a^n)%p where p is prime
+#include<bits/stc++.h>
+using namespace std;
+int modulararithmetic(int base,int power,int p)
+{
+  int result=1;
+  while(power)
+  {
+    if(power%2)
+    {
+      result=(result*base)%p;
+      power--;
+    }
+    else
+    {
+      base=(base*base)%p;
+      power=power/2;
+    }
+  }
+  return power;
+}

From df26468b9dac9de68552374a439beb9ed7d4c7c9 Mon Sep 17 00:00:00 2001
From: Rishu Rajan <56962548+RishuRajan@users.noreply.github.com>
Date: Thu, 1 Oct 2020 21:14:18 +0530
Subject: [PATCH 3/3] Create RabinKrabAlgorithm

---
 String_Algo/RabinKrabAlgorithm | 48 ++++++++++++++++++++++++++++++++++
 1 file changed, 48 insertions(+)
 create mode 100644 String_Algo/RabinKrabAlgorithm

diff --git a/String_Algo/RabinKrabAlgorithm b/String_Algo/RabinKrabAlgorithm
new file mode 100644
index 0000000..2291f44
--- /dev/null
+++ b/String_Algo/RabinKrabAlgorithm
@@ -0,0 +1,48 @@
+//This Algorithm is badically helpful in Pattern Searching
+/* pat -> pattern 
+	txt -> text 
+	q -> A prime number 
+*/
+Algorithm given in the CLRS book */
+#include <bits/stdc++.h>
+using namespace std;
+#define d 256                         // d is the number of characters in the input alphabet 
+void rabinkrabsearch(char pat[], char txt[], int q) 
+{ 
+	int M = strlen(pat); 
+	int N = strlen(txt); 
+	int i, j; 
+	int p = 0; // hash value for pattern 
+	int t = 0; // hash value for txt 
+	int h = 1; 
+	for (i = 0; i < M - 1; i++) 
+		h = (h * d) % q; 
+	for (i = 0; i < M; i++) 
+	{ 
+		p = (d * p + pat[i]) % q; 
+		t = (d * t + txt[i]) % q; 
+	} 
+	for (i = 0; i <= N - M; i++) 
+	{ 
+		if ( p == t ) 
+		{ 
+			for (j = 0; j < M; j++) 
+			{ 
+				if (txt[i+j] != pat[j]) 
+					break; 
+			} 
+			if (j == M) 
+				cout<<"Pattern found at index "<< i<<endl; 
+		} 
+
+		if ( i < N-M ) 
+		{ 
+			t = (d*(t - txt[i]*h) + txt[i+M])%q; 
+
+			// We might get negative value of t, converting it 
+			// to positive 
+			if (t < 0) 
+			t = (t + q); 
+		} 
+	} 
+}