adding modf pow and round

srcs/ft_round.c

@@ -0,0 +1,28 @@
+#include "libft.h"
+
+/**
+ * round  x to the nearest integer,
+ * but round halfway cases away from zero, regardless of the current rounding direction
+ */
+double ft_round(double x)
+{
+    // Handle special cases
+    if (x != x)
+    {             // Check for NaN (NaN is not equal to itself)
+        return x; // Return NaN
+    }
+    if (x == (double)LLONG_MAX + 1.0 || x == (double)LLONG_MIN - 1.0)
+    {
+        return x; // Return ±Infinity or the original value if overflow would occur
+    }
+
+    // Handle positive and negative numbers
+    if (x >= 0)
+    {
+        return (double)(long long)(x + 0.5);
+    }
+    else
+    {
+        return (double)(long long)(x - 0.5);
+    }
+}