Basic summary of C language (i) Summary of----------functions and systems

1. Function classification 1) No parameter no return value function is generally used to perform certain fixed functions. (Print logo) 2) No parameter a return value function is generally used to get some data or results. (Get the number) 3) There are no return value functions that generally use parameters to accomplish certain functions.     (based on the incoming number to generate the star matrix) the transfer process of the real participation parameter, two parameters are irrelevant. 4) The function of the returned value is usually used to process the data and get the result of processing. (Data conversion, calculation and statistical consolidation data) 2. Recursive functions1) Recursion needs to be able to jump out only makes sense2) The keynote function is the function being tuned      Case:  1. Arithmetic progression      1 3 5 7 9...               2. Factorial      1 2 6 120...               3. Fibonacci Series      1 1 2 3 5 8 13...               4. Power functions      1 2 4 8 64...               5. Quick Sort 3. Conversion conversion       Converting between conversions is shown in the following table: 1010 1011 TD valign= "Top" width= "> TD valign= "Top" width= ">

decimal	Octal	hex	binary		decimal	octal	hex	binary
0	< Span lang= "en-us" xml:lang= "en-US" >00	0x0	0		8	010	0x8	1000
1	< Span lang= "en-us" xml:lang= "en-US" >01	0x1	1		9	011	0x9	1001
2	< Span lang= "en-us" xml:lang= "en-US" >02	0x2	Ten		10	012	0xa
3	< Span lang= "en-us" xml:lang= "en-US" >03	0x3			11	013	0xb
4	< Span lang= "en-us" xml:lang= "en-US" >04	0x4	+		12	014	0xc	1100
5	< Span lang= "en-us" xml:lang= "en-US" >05	0x5	101		13	015	0xd	1101
6	< Span lang= "en-us" xml:lang= "en-US" >06	0x6			14	016	0xe	1110
7	07	0x7	111		15	017	0xf	1111

4. Common conversion of the binary2: Divided by 2 to reverse the remainder method (decimal part multiplied by 2 rounding) 2-10: Right-click Expansion2-A:4 in 1 method. Integer part from right to left 4 is a group, fractional part from left to right 4 one Group, not enough to fill 0. Then each group is converted individually.2:1 Split 4 method. That is, each digit is split into 4 binary. 2-8: 3 -in-18-2:1 demolition 3 5. Original code anti-code and complement positive: anti-code= = Complement = = Original code Negative Number: The original code is the symbol+ BinaryReverse Code = = Original code In addition to symbol bit inversion complement = = anti-code + 1 6. Bit operation 1) AT &1 1 (Agreed) Convert a number to a 2 binary display 2) Bitwise OR | Same 0 get 0 (Brass Bell 3) bitwise XOR or ^ same as 0 different for 1 4) bitwise reverse ~ to = 0 5) shift left << leftn bits are like the N-Times multiplied by 2 6) Right shift >> right shiftn bits are like the n-th-squared divided by 2

Basic summary of C language (i) Summary of----------functions and systems