From 6c79e4d908d459ea2c519a1a796a50e36eb5f21b Mon Sep 17 00:00:00 2001
From: Sahil Malik <sahilmalikroorkee@gmail.com>
Date: Sat, 16 Oct 2021 14:58:12 +0530
Subject: [PATCH] Create Ternary_search.c

Adding ternary search algo
---
 C/Ternary_search.c | 85 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 85 insertions(+)
 create mode 100644 C/Ternary_search.c

diff --git a/C/Ternary_search.c b/C/Ternary_search.c
new file mode 100644
index 0000000..6cdb975
--- /dev/null
+++ b/C/Ternary_search.c
@@ -0,0 +1,85 @@
+// C program to illustrate
+// recursive approach to ternary search
+ 
+#include <stdio.h>
+ 
+// Function to perform Ternary Search
+int ternarySearch(int l, int r, int key, int ar[])
+{
+    if (r >= l) {
+ 
+        // Find the mid1 and mid2
+        int mid1 = l + (r - l) / 3;
+        int mid2 = r - (r - l) / 3;
+ 
+        // Check if key is present at any mid
+        if (ar[mid1] == key) {
+            return mid1;
+        }
+        if (ar[mid2] == key) {
+            return mid2;
+        }
+ 
+        // Since key is not present at mid,
+        // check in which region it is present
+        // then repeat the Search operation
+        // in that region
+ 
+        if (key < ar[mid1]) {
+ 
+            // The key lies in between l and mid1
+            return ternarySearch(l, mid1 - 1, key, ar);
+        }
+        else if (key > ar[mid2]) {
+ 
+            // The key lies in between mid2 and r
+            return ternarySearch(mid2 + 1, r, key, ar);
+        }
+        else {
+ 
+            // The key lies in between mid1 and mid2
+            return ternarySearch(mid1 + 1, mid2 - 1, key, ar);
+        }
+    }
+ 
+    // Key not found
+    return -1;
+}
+ 
+// Driver code
+int main()
+{
+    int l, r, p, key;
+ 
+    // Get the array
+    // Sort the array if not sorted
+    int ar[] = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 };
+ 
+    // Starting index
+    l = 0;
+ 
+    // length of array
+    r = 9;
+ 
+    // Checking for 5
+ 
+    // Key to be searched in the array
+    key = 5;
+ 
+    // Search the key using ternarySearch
+    p = ternarySearch(l, r, key, ar);
+ 
+    // Print the result
+    printf("Index of %d is %d\n", key, p);
+ 
+    // Checking for 50
+ 
+    // Key to be searched in the array
+    key = 50;
+ 
+    // Search the key using ternarySearch
+    p = ternarySearch(l, r, key, ar);
+ 
+    // Print the result
+    printf("Index of %d is %d", key, p);
+}