first Occurence

Author: ganeshGhode2002

Arrays/BinarySearch/findFirstOccurence.cpp

@@ -0,0 +1,38 @@
+#include <iostream>
+using namespace std;
+
+void findFirstOccurence(int arr[], int n, int target, int &index)
+{
+    int s = 0;
+    int e = n - 1;
+
+    while (s <= e)
+    {
+        int mid = s + (e - s) / 2;
+
+        if (arr[mid] == target)
+        {
+            index = mid;
+            e = mid - 1;
+        }
+        else if (arr[mid] < target)
+        {
+            s = mid + 1;
+        }
+        else if (arr[mid] > target)
+        {
+            e = mid - 1;
+        }
+    }
+}
+
+int main()
+{
+    int arr[] = {1, 2, 3,3, 5, 6, 7, 9};
+    int n = 8;
+    int target = 1;
+    int index = -1;
+
+    findFirstOccurence(arr, n, target, index);
+    cout << "the index is : " << index;
+}