Simplification of C program algorithms

For more information about C program algorithm simplification-Linux general technology-Linux technology and application, see the following. I have read some algorithms in recent days and found that the class-based algorithms written in C are relatively good:
There are thousands of programs with high complexity, but those with low complexity are limited and often unique. There are several ways to turn high-complexity algorithms into low-complexity algorithms:
1. Changing the nesting of multiple condition sentences into a loop sentence:

Example: Income Tax
("Y" indicates income tax, and "x" indicates monthly income ).
[Table = 390] [tr] [td]
[/Td] [td] 0; x <= 2000; [/td] [/tr] [tr] [td] [/td] [td] (x-2000) * 3%; 2000 100000; [/td] [/tr] [/table]
General idea:
Use a nested multi-Condition Statement:
# Include
Mian ()
{
Flaot x, y;
Scanf ("% f", & x );
If (x <= 2000)
Y = 0;
Else
If (x <= 5000)
Y = (x-2000) * 0.03;
Else
If (x <= 10000)
Y = (X-5000) * 0.05 + 90;
Else
If (x <= 100000)
Y = (x-10000) * 01 + 340;
Else
Y = (x-100000) * 0.3 + 9340;
Printf ("% f", y );
}
This kind of program is really nice, but not universal (the so-called general, that is, the program that only changes data without changing the program after the situation changes ).
The following is a common algorithm for comparison:
# Include "stdio. h"
# Define N 4
Void main ()
{
Float a [N + 1] = {100000 },
B [N + 1] = {0.0, 0.01, 0.05, 0.1, 0.3 },
C [N] = {0, 90, 340,9340 };
Float x, y;
Int I;
Printf ("Please input your Wages :");
Scanf ("% f", & x );

/* This section is added to me to prevent input format errors.
While (1)
{
If (x> = 0)
Break;
Else
{
Printf ("ERROR! \ NPlease input your Wages again :");
Scanf ("% f", & x );
}
}
*/
I = N;
While (x <= )
I = I-1;
Printf ("% f % d", y, I );
Y = (x-) * B+ C [I-1];

/* I prefer to use the for Loop
For (I = N; x; I --);
Y = (x-) * B+ C [I-1];
*/
Printf ("tax payable: % f", y );
}
In this way, you do not need to modify the program even if you need to modify the data, and the complexity of the program is greatly reduced.