C++ code for Linear and Binary Search been added

day28/C++/Linear_Search.cpp

@@ -0,0 +1,48 @@
+/**
+ * @author: Karthick < karthikn2099@gmail.com >
+ * @github: https://github.com/karthikn2098
+ * @date: 31/01/2018
+ */
+
+#include <iostream>
+using namespace std;
+
+/** @desc: compares the key with each array elements.
+  * @param: array , key (to be found), size of the array.
+  * @return: index of key if present , -1 otherwise.
+  * @TimeComplexity: O(n)   < n = size of the array >
+  */
+int linear_search(int* arr , int key, int N) {
+
+    for( int i = 0 ; i < N ; i++ ) {
+        if(arr[i] == key) {
+            return i;
+        }
+    }
+
+    return -1;
+}
+
+int main(void) {
+
+    int arr[] = { 12, 15, 1, 16, 20, 100, 89, 97, 205, 345, 467 };
+
+    int sizeOfArray = sizeof(arr) / sizeof(arr[0]);
+
+    cout << "\nLinear_search(arr , 20) = " << linear_search(arr, 20, sizeOfArray ) << endl;
+
+    cout << "\nLinear_search(arr , 1000) = " << linear_search(arr, 1000, sizeOfArray ) << endl;
+
+    return 0;
+}
+
+/*
+---------------
+ Sample Output
+---------------
+
+Linear_search(arr , 20) = 4
+
+Linear_search(arr , 1000) = -1
+
+*/

day29/C++/Binary_Search.cpp

@@ -0,0 +1,59 @@
+/**
+ * @author: Karthick < karthikn2099@gmail.com >
+ * @github: https://github.com/karthikn2098
+ * @date: 31/01/2018
+ */
+
+#include <iostream>
+using namespace std;
+
+/** @desc: splits the array into two sections at each step, then checks the element in the desired one.
+  * @param: array , key (to be found), size of the array.
+  * @return: index of key if present , -1 otherwise.
+  * @TimeComplexity: O( logn )   < n = size of the array >
+  */
+int Binary_search(int arr[] , int key, int N) {
+
+    int low = 0 , high = N-1 , mid;
+
+    while(low <= high) {
+
+        mid = low + (high - low) / 2;   //like (low + high)/2 but efficient.
+
+        if(key == arr[mid]) {
+            return mid;
+        }
+        else if( key > arr[mid] ) {
+            low = mid + 1;
+        }
+        else {
+            high = mid - 1;
+        }
+    }
+
+    return -1;
+}
+
+int main(void) {
+
+    int arr[] = { 1, 3, 5, 7, 8, 9, 100, 234, 788, 899 };
+
+    int sizeOfArray = sizeof(arr) / sizeof(arr[0]);
+
+    cout << "\nBinary_search(arr , 100) = " << Binary_search(arr, 100, sizeOfArray ) << endl;
+
+    cout << "\nBinary_search(arr , 1000) = " << Binary_search(arr, 1000, sizeOfArray ) << endl;
+
+    return 0;
+}
+
+/*
+---------------
+ Sample Output
+---------------
+
+Binary_search(arr , 100) = 6
+
+Binary_search(arr , 1000) = -1
+
+*/