First, FIG Mind
Second, the concept of summary,
1. The data structure definition :the data structure is a way to store and organize data in order to access and modify. Data structure includes a logical structure of data, data storage structure and operation data, i.e., organized according to a certain number of logic data, according to a certain map stored in the manner that the memory of the computer, and the data defined in the a collection of operations.
Logical structure data of: reflecting the relationship between the data elements. There are a set of linear, tree structure, FIG structure .
2. Data storage structure : logical structure in the computer memory map, logical structure implemented in a computer, comprising the elements shown and represents the relationship between data elements. Sequential storage structure (array), the chain storage structure (linked list), the index storage structure, hash storage structure.
3. Data operation: through the algorithm description, to understand the overall quality of the program.
4. About algorithm:
(1) Characteristic: an input; zero or more input
Output: one or more outputs, to reflect the results of processing the input data
There are poor: the algorithm must terminate after a finite number of steps executed
The exact nature: each step of the algorithm must have a precise definition
Feasibility: Any calculation step in the algorithm is executed can be decomposed into basic operations executable step, i.e., each step can be calculated for a limited time
( 2) requirements : correctness: the algorithm designed to meet the needs of specific issues, and any legal input will draw the correct output;
Readability: refers to the following algorithm is written, ease of understanding of the algorithm. If an algorithm is more abstract and difficult to understand, then the algorithm is not conducive to the exchange and to promote the use, for the modification, extension, maintenance is very inconvenient, therefore, in the pursuit of efficiency, but also should be a straightforward algorithm as far as possible.
Robustness: When the input data is illegal, the algorithm will make the appropriate judgment, and not because of erroneous input caused paralysis.
High time efficiency (time complexity) and require less storage space (spatial complexity degrees)
( 3) time and space complexity :
Time: Algorithm execution times, denoted by T (n) = O (f (n)), said O (f (n)) progressive time complexity of the algorithm
Space: The algorithm consumes storage space
5: the structure has been learned : stack, queue, strings (mind mapping are described generally)
Third, difficult problems and solutions,
PTA is subject to write slower, less fundamental problems, errors are to be answered by asking the students have written. Control through the code and explain the students to solve.