Standard C language summary 4

Labyrinth :

    Data analysis :

        1. Define a two-dimensional character array as a maze map

        2. Define the location of the variable record role x y

        3. Time :time(NULL)   obtain 1970-1-1 The total number of seconds passed by the runtime

    logic analysis :

        Into the dead cycle :

        1. Show map

        2. Get the direction key and process it

            Judge whether the road ahead ' '

                If it is :

                    1. Turn the old location into ' '

                    2. Turn the new location into '@'

                    3. Update character position coordinates x y

        3. Determine whether to reach the exit

            If it is : Program end

tuixiangzi : Data analysis :

            1. Determine the correspondence between numeric values and characters

                0   ' '

                1   '@'

                2   '$'

                3   '#'

                4   'o'

                5   '@'

                7   '$'

            2. Definition 8*8 Integer map and initialize

            3. Define variables that record the position of the role x y

            4. Variables that define the number of recording steps

        logic analysis : Into the dead cycle

            1. Clean the screen , Show map

                if(0 == map[i][j])  printf(" ");

            2. Get the direction key and process it

            3. Determine whether the game wins

                The road ahead , Refer to maze

                    In front of the +1

                    Original location -1

                    Update coordinates

                2. In front is the box

                    In front of the box is the road \ The target point

                        In front of people    +3

                        In front of people          -3+1

                        Man's original position        -1

                        ' Update left

Decimal to binary :( Convert to other base )

        Remainder method ： use 2 Balance the data , Then continue to seek surplus from the business , Until Shang Wei 0 end , The remainder generated in this process is the binary of the data ( The reverse )

Right seeking method ：

            From high position to position , data  2^(n-1) If it's enough , So the first n Bit is 1, Otherwise, it would be 0, Until the data is reduced to 0

Binary to decimal : ( Other decimal system to decimal system m^(n-1))

        Everyone's 2^(n-1) Sum up

C In language , With 0 The starting number is octal , With 0x The first number is hexadecimal

Original code : Binary of data

    Inverse code :

        The inverse code of a positive number is his original code

        The inverse code of a negative number is its original code except for the sign bit , Other bits are inversed bit by bit

    Complement code :

        The complement of a positive number is its original code

        The complement of a negative number is its inverse +1

Complement to data :

        Unsigned complement is directly converted to decimal

        The highest sign is 0, The description is positive , It is also directly converted to decimal

        Signed and the highest bit is 1;

An operator     &   |   ~   ^   <<  >>

    A   &   B   Press phase and   Different for 0

    A   |   B   Press bit or     Different for 1

   ~A           Reverse by position

    A   ^   B   Bitwise XOR     Same as 0, Dissimilarity is 1

   A   <<  n   hold A The complement of moves to the left n position , Left discard , The right to repair 0

   A   >>  n   hold A The complement of moves to the right n position , On the right side of the discarded , Fill in the sign on the left , The highest bit is 1 Time compensation 1, by 0 repair 0

Custom function

            To better manage your own code , Reduce the redundancy of the code and encapsulate the code into a functional form

            Function declaration :

                Implicitly declare : When the function is called , There is no previous declaration or definition of this function

                        An implicit warning will be generated , Parameters will be guessed based on actual parameters ,

                        The return value will be guessed as int Type should not generate implicit declarations anyway

                        As long as there is a declaration or definition before the call

                The purpose of function declaration is to tell other code the calling format of the function

                return type   Function name ( type 1 The name of the parameter 1, type 2 The name of the parameter 2,...);

Be careful :

            1, There is a function definition before the function call , Then the function declaration can be omitted

            2, The return value of the function will be returned at the call location , Can be displayed immediately ,

            You can also use variables to record

            3, A function is recommended not to exceed 50 Line code