Merge pull request WebClub-NITK#444 from geekgeekvm/master

Fibonacci Search

Fibonacci_Search/geekgeekvm.c

@@ -0,0 +1,63 @@
+#include <stdio.h>
+
+int min(int x, int y) { return (x<=y)? x : y; }
+
+
+int fibMonaccianSearch(int arr[], int x, int n)
+{
+
+    int fibMMm2 = 0;   // (m-2)'th Fibonacci No.
+    int fibMMm1 = 1;   // (m-1)'th Fibonacci No.
+    int fibM = fibMMm2 + fibMMm1;  // m'th Fibonacci
+
+
+    while (fibM < n)
+    {
+        fibMMm2 = fibMMm1;
+        fibMMm1 = fibM;
+        fibM  = fibMMm2 + fibMMm1;
+    }
+
+    int offset = -1;
+
+
+    while (fibM > 1)
+    {
+        int i = min(offset+fibMMm2, n-1);
+
+
+        if (arr[i] < x)
+        {
+            fibM  = fibMMm1;
+            fibMMm1 = fibMMm2;
+            fibMMm2 = fibM - fibMMm1;
+            offset = i;
+        }
+
+
+        else if (arr[i] > x)
+        {
+            fibM  = fibMMm2;
+            fibMMm1 = fibMMm1 - fibMMm2;
+            fibMMm2 = fibM - fibMMm1;
+        }
+
+
+        else return i;
+    }
+
+    if(fibMMm1 && arr[offset+1]==x)return offset+1;
+
+    return -1;
+}
+
+int main(void)
+{
+    int arr[] = {10, 22, 35, 40, 45, 50, 80, 82,
+                 85, 90, 100};
+    int n = sizeof(arr)/sizeof(arr[0]);
+    int x = 85;
+    printf("Found at index: %d",
+            fibMonaccianSearch(arr, x, n));
+    return 0;
+}