warring implicit declaration of function

The warning "implicit declaration of function" occurs when you use a function without declaring it or including the header file that contains its declaration. In C, functions need to be declared before they are used.

To resolve this warning, you need to do one of the following:

1. Include the header file that contains the function declaration at the top of your source file. For example, if you are using a function from the math library, you should include the math.h header file.

2. Declare the function before using it. You can do this by adding a function prototype before the function call. A function prototype specifies the return type and parameters of a function. For example:

   // Function prototype
   int myFunction(int arg1, double arg2);

   // Function call
   myFunction(10, 3.14);

3. If you are using a function from a different source file, you may need to link against the object file or library that contains the function definition during the compilation process.

Make sure to check if you have misspelled the function name or forgot to include the necessary header files.