| This work belongs courses | C Programming Language Ⅰ |
|---|---|
| Where the job requires | https://www.cnblogs.com/tongyingjun/p/11695948.html |
| My aim in this course is | Master for loop and three expressions statement, statement of preliminary understanding pow usage |
| In particular aspects of the job which helped me achieve goals | PTA five jobs, and the compiler may write their own code and code errors |
| references | C Programming Language, literature Baidu |
1.PTA lab assignments
1.1 in Simple sequence before interleaving N items and
present questions require programming, calculates sequence - 1/4 + 1/7 - 1/10 ... of the first N + sum. In a given input row positive integer N. Output format: output section and in accordance with the value of S "sum = S" format in a row, accurate to three decimal places. Title ensure that the calculation result does not exceed the double precision.
⑴ data processing
① expression data: int This problem with the plastic structure, the variables and inf sum, sum is the dependent variable, varies with changes in n.
② Data processing: Use the for loop structure and if-else statements, the second circulation inside the braces is the content, wherein the selective structure.
⑵ experiment code shots
⑶ create test data
| Input data | Output Data | Explanation |
|---|---|---|
| 2 | 0.750 | >1 |
| 10 | 0.819 | >9 |
| 100 | 0.834 | >99 |
| 101 | 0.837 | >100 |
⑷PTA submit list describes the
cause of the error
Q1 compile error: in their own compiler compiler above sum no matter what the input is zero, I think that this problem so the compiler has to pay on the PTA interview, the result is wrong.
A1: find yourself behind the sum entered in the code above is wrong, the output becomes 0 S.
Q2 compile error: Compiler face on their copy above PTA will have a compilation error.
A2: ask the assistant, the result is I forget to copy the leading #.
1.2 seeking interleaving sequence and first N
Questions require programming, the sequence of staggered 1-2 / 3 + 3 / 5-4 / 7 + 5 / 9-6 / 11 + ... and the sum of the first N. Input format: In the given input row a positive integer N. Output format: output section and a value in a row, the results of three decimal places.
⑴ data processing
① Expression Data: The title structure was used int plastic, variable in. There are double precision floating point, due to the variable sum varies with changes in n.
② Data Processing: The title used for the loop structure, the second content inside the braces are circular, scanf format control characters are used to input data. Meanwhile POW () is math, h for calculating the power of x to y, the title is a molecule.
⑵ experiment code screenshots
⑶ create test data
| Input data | Output Data | Explanation |
|---|---|---|
| 5 | 0.917 | >1 |
| 11 | 0.904 | >10 |
| 100 | 0.391 | >99 |
| 101 | 0.894 | >100 |
⑷PTA submit a list of instructions
Cause of error
Q1 compile error: Compiler Error in place of the above their math.h not entered in the second line
A1: In the Baidu search above came to realize after the
Q2 compilation error: Do not know the for loop structure in this application pow structure so wrong a few times.
A2: own in the book above information checked Baidu also saw above came to understand a little bit.
Q3 compilation errors: in front of the double-precision floating-point application, inside the back printf% lf mistyped.
A3: valiant think of it written in the book above.
2. Code peer assessment
⑴ students Code shots (three shifts from the software has good students)
own codes shots (7.3)
⑵ comparison
the same point: the use of plastic int and double and double precision floating point, there is a structure of pow
differences: ① different variables used
② loop structure inside the contents of different
two compared, had good students is relatively simple, he's the number of lines of code than I, more complicated. My relatively simple.
summarize
⑴ learning progress bar
| Week / Date | This week the time spent | Lines of code | Learned knowledge Introduction | Currently more confusing issues |
|---|---|---|---|---|
| the fourth week | Four hours | 85 | I learned a for loop in Baidu above a preliminary understanding of the usage of pow | pow usage as well as cyclic structure |
⑵ cumulative number of lines of code and blog
3.3 Summary and perception of learning content
⑴ learning content summary
① learned this lesson on how to use the looping structure for statements, know for a general expression for the statement to use two semicolons to separate the three expressions, in the middle there is a call for statement cycle control variables.
② know the meaning of the statement in the middle of three expressions for and how to use.
③ own C language is not very understanding but also to learn a lot of knowledge, learning only book the above is not enough, you also need to own additional study.
④ while knocking in the middle of the code works with those who remember their place was wrong and remind yourself not to make the same mistake next time.
⑵ learning experience
① with expertise in learning to understand things more and more.
② knowledge to know how much your code is also more, know more than the previous error code when a little faster to find the wrong place.
③ themselves in knocking the code when the speed is also fast, but some common mistakes still occur, it is not careful, looking for the wrong time should be careful.
④ the profession to own a lot to learn outside school hours, we also have to knock a bit of code, the only way to improve yourself.