I am taking CS50x and in PSet 2: Readability throws me the following error when compiling:
Image of the Error message below, easier to read
readability/ $ make readability
readability.c:52:24: error: multi-character character constant [-Werror,-Wmultichar]
if ((txt[i] >= '97' && txt[i] <= '122') || (txt[i] >= '65' && txt[i] <= '90'))
^
fatal error: too many errors emitted, stopping now [-ferror-limit=]
2 errors generated.
make: *** [: readability] Error 1
I think it has to be an issue that 97 and all other ASCII codes I am using are not recognized as integers, do I need to specifically declare them? If so, how?
Here is my code:
#include <cs50.h>
#include <stdio.h>
#include <ctype.h>
#include <string.h>
#include <math.h>
int count_letters(string);
int count_words(string);
int count_sentences(string);
float l;
float w;
float s;
int main(void)
{
// Ask user for string, store in txt.
string txt = get_string("Enter your text: ");
int i = strlen(txt);
// Convert letters and sentences to avg / 100 w.
float L = 100 * (l / w);
float S = 100 * (s / w);
// Calc coleman-liau index
int clindex = round(0.0588 * L - 0.296 * S -15.8);
// Printf "Grade X" if X > 16, printf "Grade 16+".
if (clindex < 1)
{
printf("Grade < 1\n");
}
else if (clindex > 16)
{
printf("Grade 16+\n");
}
else
{
printf("Grade %i\n", clindex);
}
}
int count_letters(string txt)
{
// Count letters
l = 0;
for (int i = 0, n = strlen(txt); i < n; i++)
{
// If the txt is between a-z (97 - 122) or A-Z (65 - 90), increase letter count.
if ((txt[i] >= '97' && txt[i] <= '122') || (txt[i] >= '65' && txt[i] <= '90'))
{
l++;
}
}
return l;
}
int count_words(string txt)
{
// Count words
w = 1;
for (int i = 0, n = strlen(txt); i < n; i++)
{
// If there is a space (ascii 32), then increase word count.
if (txt[i] == 32)
{
w++;
}
}
return w;
}
int count_sentences(string txt)
{
// Count sentences
s = 0;
for (int i = 0, n strlen(txt); i < n; i++)
{
// If txt is . (period 46), ! (exclamation 33), or ? (question 63), inscrease sentence count.
if (txt[i] == 46 || txt[i] == 33 || txt[i] == 63)
{
s++;
}
}
return s;
}
Thank you all for your help.
This code is the problem
if ((txt[i] >= '97' && txt[i] <= '122') || (txt[i] >= '65' && txt[i] <= '90'))
Try this
if (isalpha(txt[i]))
'' quotes are for single character literals.
'a' or 'd' for example.
'123' is more than one character literal.
You probably want to use plain integers instead:
(txt[i] >= 97 && txt[i] <= 122)
Related
When I run my code, the outcome has failed to show the exact result based on the texts given in the problem set. Although, it showed the grade, the result is incorrect. The text is : "Would you like them here or there? I would not like them here or there. I would not like them anywhere."(Grade 2)
enter image description here
Supposedly, the result for the text is "Grade 2". However, it shows all grades instead.
enter code here
int main(void)
{
string s = get_string("Text: ");
printf("%s\n",s);
int count_letters = 0; //To count letters (uppercase & lowercase)
int count_words = 1; //To count words
int count_sentences = 0; //To count sentences
for (int i = 0; i < strlen(s); i++)
if (isalpha(s[i]))
{
if ((s[i] >= 'a' && s[i] <= 'z' )||( s[i] >= 'A' && s[i] <= 'Z'))
{
count_letters++;
}
if (s[i] == ' ')
{
count_words++;
}
if (s[i] == '.' || s[i] =='!' || s[i] == '?')
{
count_sentences++;
}
//printf("%i count_letter(s)\n", count_letters);
//printf("%i count_words(s)\n", count_words);
//printf("%i sentence(s)\n", count_sentences);
//Coleman-Liau index
float L = (count_letters / (float) count_words) * 100;
float S = (count_sentences / (float) count_words) * 100;
int grade = round (0.0588 * L - 0.296 * S -15.8);
if (grade < 1)
{
printf("Before Grade 1\n");
}
else if (grade >= 16)
{
printf("Grade 16+\n");
}
else
{
printf("Grade %.d\n", grade);
}
}
}
Is there any problem with my code? How can I fix my code in order to receive the exact outcome. I've been doing this problem set for almost 2 days :'/. Thanks in advance
Calculate the number of letters, sentences, and words inside of the loop and calculate Coleman-Liau's index outside of the loop.
Don't calculate something in a loop and try to get specific output from within it as well, it never ends well. So in conclusion, calculate your values in the loop and do everything else outside of it.
int count_letters = 0; //To count letters (uppercase & lowercase)
int count_words = 1; //To count words
int count_sentences = 0; //To count sentences
for (int i = 0; i < strlen(s); i++){
// get the amounts in the loop
if (isalpha(s[i]))
{
if ((s[i] >= 'a' && s[i] <= 'z') || (s[i] >= 'A' && s[i] <= 'Z'))
{
count_letters++;
}
if (s[i] == ' ')
{
count_words++;
}
if (s[i] == '.' || s[i] == '!' || s[i] == '?')
{
count_sentences++;
}
}
}
//Calculate Coleman-Liau outside of it and get the correct grade from your if statements
Since you have three distinct categories to count, I would create a function for each of these.
For example, based on your code, you could create a function to count characters (you don't need isdigit function here, non-digit characters are already filtered out by the algorithm itself):
int get_letters_count(char *text_str)
{
int count_letters = 0;
int text_len = strlen(text_str);
for (int i = 0; i < text_len; i++) {
if ( (text_str[i] >= 'a' && text_str[i] <= 'z')
|| (text_str[i] >= 'A' && text_str[i] <= 'Z')
|| (text_str[i] >= '0' && text_str[i] <= '9')) {
count_letters++;
}
}
return count_letters;
}
This approach of breaking down your program will make it much easier to develop.
Here is a very crude implementation based on the Coleman–Liau index Wikipedia page:
#include <stdio.h>
#include <string.h>
#include <stdbool.h>
int get_letters_count(char *text_str)
{
int count_letters = 0;
int text_len = strlen(text_str);
for (int i = 0; i < text_len; i++) {
if ( (text_str[i] >= 'a' && text_str[i] <= 'z')
|| (text_str[i] >= 'A' && text_str[i] <= 'Z')
|| (text_str[i] >= '0' && text_str[i] <= '9')) {
count_letters++;
}
}
return count_letters;
}
int get_words_count(char *text_str)
{
int count_words = 0;
int text_len = strlen(text_str);
for (int i = 0; i < text_len; i++) {
if (text_str[i] == ' ') {
count_words++;
}
}
if (count_words)
count_words++;
return count_words;
}
bool word_is_acronym(char *word)
{
bool ret = true;
for (; *word && *word != ' '; word++) {
if ( *word != '.'
&& *word < 'A' || *word > 'Z') {
ret = false;
}
}
return ret;
}
int get_sentences_count(char *text_str)
{
int count_sentences = 0;
int text_len = strlen(text_str);
char *last_word = &text_str[0];
for (int i = 0; i < text_len; i++) {
if ( text_str[i] == ' '
&& i < (text_len - 1)) {
last_word = &text_str[i + 1];
}
bool end_mark = text_str[i] == '.'
|| text_str[i] == '!'
|| text_str[i] == '?';
if ( end_mark
&& word_is_acronym(last_word) == false) {
count_sentences++;
}
}
return count_sentences;
}
int main(void)
{
char text_str[] = "Existing computer programs that measure readability are based "
"largely upon subroutines which estimate number of syllables, "
"usually by counting vowels. The shortcoming in estimating syllables "
"is that it necessitates keypunching the prose into the computer. "
"There is no need to estimate syllables since word length in letters "
"is a better predictor of readability than word length in syllables. "
"Therefore, a new readability formula was computed that has for its "
"predictors letters per 100 words and sentences per 100 words. "
"Both predictors can be counted by an optical scanning device, and "
"thus the formula makes it economically feasible for an organization "
"such as the U.S. Office of Education to calibrate the readability of "
"all textbooks for the public school system.";
int count_letters = get_letters_count(text_str);
int count_words = get_words_count(text_str);
int count_sentences = get_sentences_count(text_str);;
if ( count_letters > 0
&& count_words > 0
&& count_sentences > 0) {
float L = ((count_letters * 100) / count_words);
float S = ((count_sentences * 100) / count_words);
float grade = 0.0588 * L - 0.296 * S - 15.8;
printf("grade = %.01f\n", grade);
} else {
printf("bad input\n");
}
}
Ouput:
$ gcc main.c && ./a.out
grade = 14.5
Parsing text can be very trick, though.
Once you get a first version working with a known input such as this, try to expand your data set and keep improving your program.
This program is also far from being computationally efficient. If that becomes a bottleneck, you could optimize the functions or maybe reduce the number of loops grouping the functions in a single loop.
Certainly most times it's better to start with a crude working solution and improve from there instead of attempting a more sophisticated/complete solution right from the beginning.
so this is my function. My main focus is to get the character frequencies and the highest character frequency.
The function below (get_letter_frequencies) is supposed to get a string example ("I am a big boy") and return the character frequencies and the highest character frequency.
The Function should return
i - 2
a - 2
m - 1
b - 2
g - 1
o - 1
y - 1
Highest character frequency would be " iab "
My problem is with the get_letter_frequencies function. What should I arrange from the function in order to return the above output?
void get_letter_frequencies(const char *text, size_t len, int freq[26], int *max_freq)
{
for(int i = 0; i<len; i++)
{
if(text[i] != ' ' || !(is_sentence_terminator(text[i]))) //this condition is set in order to ignore the spaces and the sentence terminators (! ? .)
{
if(text[i] >= 'a' && text[i] <= 'z')
{
freq[text[i] - 'a']++;
}
}
}
for(int j = 0; j < 26; j++)
{
if(freq[j] >= 1)
{
*max_freq = freq[j];
}
}
This function below(is_sentence_terminator). Here the function checks whether the sentence finishes with a " ! ? or . " if it does not finish with one of the terminators then it is not a sentence and ignores it.
int is_sentence_terminator(char ch)
{
if(ch == 33 || ch == 46 || ch == 63)
{
return 1;
}else
{
return 0;
}
}
There are some issues in your code:
there is no need to test for special characters, comparing text[i] to 'a' and 'z' is sufficient for ASCII systems.
in the second loop, you should update *max_freq only if freq[j] is greater than the current value, not 1. *max_freq should be initialized to 0 before the loop.
In the calling code, you would also
print the letters whose frequency is non 0.
print all letters with the maximum frequency using one final loop.
Here is a modified version:
void get_letter_frequencies(const char *text, size_t len, int freq[26], int *max_freq) {
for (int i = 0; i < 26; i++)
freq[i] = 0;
for (int i = 0; i < len; i++) {
if (text[i] >= 'a' && text[i] <= 'z') {
freq[text[i] - 'a']++; // assuming ASCII
}
}
*max_freq = 0;
for (int i = 0; i < 26; i++) {
if (*max_freq < freq[i]) {
*max_freq = freq[i];
}
}
}
I seem to have made a mistake in my code but I can't find it.
All reading grades give me the correct grade, except for grade 7 which results in grade 8.
I assume it is a rounding error of some sort?
I tested the following piece of code with and without the round() in the last function.
Without it most of the grade levels are off, with the round() in there I only get an mistake a the grade7 level.
Where is my mistake?
#include <cs50.h>
#include <stdio.h>
#include <ctype.h>
#include <math.h>
#include <string.h>
//Prototypes
int count_letters(string text);
int count_words(string text);
int count_sentences(string text);
int get_score (string text);
//Main function
int main(void)
{
//Get user input
string text = get_string("Text: ");
//Grade user text
int i = get_score(text);
if(i < 1)
{
printf("Before Grade 1\n");
}
else if (i > 1 && i < 16)
{
printf("Grade %i\n", i);
}
else
{
printf("Grade 16+\n");
}
}
// Extra functions
int count_letters(string text)
{
// variables
int letters = strlen(text);
int total_letters = 0;
int characters = 0;
// Loop through text and count all non-letters
for(int i = 0; i < letters; i++)
{
if((text[i] < 65 || text[i] > 95) && (text[i] < 97 || text[i] > 122))
{
characters++;
}
}
// substract all non-letters from total chars and return.
total_letters = letters - characters;
return total_letters;
}
int count_words(string text)
{
// variables
int letters = strlen(text);
int spaces = 1;
// Loop through text and count all spaces
for(int i = 0; i < letters; i++)
{
if(text[i] == ' ')
{
spaces++;
}
}
return spaces;
}
int count_sentences(string text)
{
// variables
int letters = strlen(text);
int sentence = 0;
// Loop through text and count all sentences
for(int i = 0; i < letters; i++)
{
if(text[i] == 46 || text[i] == 33 || text[i] == 63)
{
sentence++;
}
}
return sentence;
}
int get_score (string text)
{
//variables
int letters = count_letters(text);
int words = count_words(text);
int sentence = count_sentences(text);
float index = 0;
// letters divided by words * 100
float L = 100 * letters / words;
// sentences divided by words *100
float S = 100 * sentence / words;
index = round(0.0588 * L - 0.296 * S - 15.8);
return index;
}
if((text[i] < 65 || text[i] > 95) && (text[i] < 97 || text[i] > 122)) is almost certainly a bug. You probably meant to be implementing isalpha, but you did it incorrectly. You meant to write:
if((text[i] < 'A' || text[i] > 'Z') && (text[i] < 'a' || text[i] > 'z')), which would have avoided the typo in which 95 was used instead of 90. Instead of this, though, you should just use the standard library and write:
if( ! isalpha(text[i]) ) ...
Using literals like 'A' instead of the magic number 65 makes the code more readable and helps avoid trivial mistakes like this.
There are quite a few issues with your code:
As #IrAM has mentioned in a comment, your if does not handle a score of 1. Moreover, you can simplify your if checks if you start from the other end, i.e. first check for greater than 16:
int main(void)
{
//Get user input
string text = get_string("Text: ");
//Grade user text
int i = get_score(text);
if(i > 16)
{
printf("Grade 16+\n");
}
else if (i > 0)
{
printf("Grade %i\n", i);
}
else
{
printf("Before Grade 1\n");
}
}
As #Gerhardh mentions, you are dividing two integers which forces the result to be an integer too. If at least one of the operands is casted to a float, the result is type-promoted to a float:
// letters divided by words * 100
float L = 100 * (float) letters / words;
// sentences divided by words *100
float S = 100 * (float) sentence / words;
Optimizations
You have three different functions for counting words, sentences and letters. Why three loops when you can do it in one loop? Plus an additional iteration for strlen() in each function. Write a Count struct like this:
struct Count
{
int letters;
int words;
int sentences;
int length;
};
Then have one function that returns this struct. Like #WilliamPursell mentions, using character literals instead of ASCII values makes code much more readable:
Count get_count(string text)
{
Count result = {0, 1, 0, 0};
result.length = strlen(text);
int characters = 0;
// Loop through text and count all non-letters
for(int i = 0; i < count.length; i++)
{
if((text[i] < 'A' || text[i] > 'Z') && (text[i] < 'a' || text[i] > 'z'))
{
characters++;
}
if(text[i] == ' ')
{
result.words++;
}
if(text[i] == '.' || text[i] == '!' || text[i] == '?')
{
result.sentences++;
}
}
// subtract all non-letters from total chars and return.
count.letters = count.length - characters;
return result;
}
This is what get_score() will change to:
int get_score (string text)
{
//variables
Count result = get_count(text);
float index = 0;
// letters divided by words * 100
float L = 100 * (float) result.letters / result.words;
// sentences divided by words *100
float S = 100 * (float) result.sentences / result.words;
index = round(0.0588 * L - 0.296 * S - 15.8);
return index;
}
Side Note: A '.' may always not necessarily mean the end of a sentence. It has other meanings like in an acronym or as ellipsis.
In solving this readability problem, I have been getting some weird unexpected results(expected Grade 16+, getting Grade 10 etc etc), I am not being able to figure out where the bug is or how can I solve it, please help me figure out the bug. The codes are as follows:
//includes
#include <stdio.h>
#include <cs50.h>
#include <string.h>
#include <math.h>
//global variables
int lc; //letter count
int wc; //word count
int sc; //sentence count
bool awc; //already word counted
double L; //average number of letters per 100 words
double S; //average number of sentences per 100 words
float index;
//function declaration
int count_letters(string x);
int count_words(string x);
int count_sentences(string x);
//main
int main(void)
{
string text = get_string("text : ");
count_letters(text);
printf("%i letters\n", lc);
count_words(text);
printf("%i words\n", wc);
count_sentences(text);
printf("%i sentences\n", sc);
L = lc / wc * 100.0f;
S = sc / wc * 100.0f;
index = (0.0588 * L) - (0.296 * S) - 15.8;
if(index < 1)
{
printf("Before Grade 1\n");
}
else if(index >= 16)
{
printf("Grade 16+\n");
}
else
{
printf("Grade %i\n", (int) round(index));
}
}
//functions
int count_letters(string x)
{
lc = 0;
for(int i = 0, n = strlen(x); i < n; i++)
{
if((x[i] >= 'a' && x[i] <= 'z') || (x[i] >= 'A' && x[i] <= 'Z'))
{
lc += 1;
}
}
return lc;
}
int count_words(string x)
{
wc = 0;
awc = false;
for(int i = 0, n = strlen(x); i < n; i++)
{
if((x[i] >= 'a' && x[i] <= 'z') || (x[i] >= 'A' && x[i] <= 'Z'))
{
if(awc == false)
{
wc += 1;
awc = true;
}
}
if(x[i] == ' ')
{
awc = false;
}
}
return wc;
}
int count_sentences(string x)
{
sc = 0;
for(int i = 0, n = strlen(x); i < n; i++)
{
if(x[i] == '.' || x[i] == '!' || x[i] == '?')
{
sc += 1;
}
}
return sc;
}
The number of letters, words and sentences from these functions are correct so far so I think the problem lies in the main section, probably something to do with the variable type of "L" and "S" or the index formulae, please help me figure out where the problem is. Thank you
here are some of the tests: sentences(expected results)
1.One fish. Two fish. Red fish. Blue fish. (Before Grade 1)
2.Harry Potter was a highly unusual boy in many ways. For one thing, he hated the summer holidays more than any other time of year. For another, he really wanted to do his homework, but was forced to do it in secret, in the dead of the night. And he also happened to be a wizard. (Grade 5)
3.A large class of computational problems involve the determination of properties of graphs, digraphs, integers, arrays of integers, finite families of finite sets, boolean formulas and elements of other countable domains. (Grade 16+)
L = lc / wc * 100.0f;
wrong
L = 100.0f * lc / wc;
right.
When both operands of / are integers, the result is integer as well, so 5/3 == 1.
the OPs code contains several problems, as discussed in the comments to the question.
The following proposed code:
corrects those problems exposed in the comments
cleanly compiles
strongly suggest all those 'global' variables be moved to inside the appropriate functions and when needed else where be passed as parameters.
and now, the proposed code:
//includes
#include <stdio.h>
#include <cs50.h>
#include <string.h>
#include <math.h>
//global variables
int lc; //letter count
int wc; //word count
int sc; //sentence count
bool awc; //already word counted
double L; //average number of letters per 100 words
double S; //average number of sentences per 100 words
double i;
//function declaration
int count_letters(string x);
int count_words(string x);
int count_sentences(string x);
//main
int main(void)
{
string text = get_string("text : ");
count_letters(text);
printf("%i letters\n", lc);
count_words(text);
printf("%i words\n", wc);
count_sentences(text);
printf("%i sentences\n", sc);
L = lc / wc * 100.0;
S = sc / wc * 100.0;
i = (0.0588 * L) - (0.296 * S) - 15.8;
if(i < 1.0)
{
printf("Before Grade 1\n");
}
else if(i >= 16.0)
{
printf("Grade 16+\n");
}
else
{
printf("Grade %i\n", (int) round(i));
}
}
//functions
int count_letters(string x)
{
lc = 0;
for( size_t i = 0, n = strlen(x); i < n; i++)
{
if((x[i] >= 'a' && x[i] <= 'z') || (x[i] >= 'A' && x[i] <= 'Z'))
{
lc += 1;
}
}
return lc;
}
int count_words(string x)
{
wc = 0;
awc = false;
for( size_t i = 0, n = strlen(x); i < n; i++)
{
if((x[i] >= 'a' && x[i] <= 'z') || (x[i] >= 'A' && x[i] <= 'Z'))
{
if(awc == false)
{
wc += 1;
awc = true;
}
}
if(x[i] == ' ')
{
awc = false;
}
}
return wc;
}
int count_sentences(string x)
{
sc = 0;
for( size_t i = 0, n = strlen(x); i < n; i++ )
{
if(x[i] == '.' || x[i] == '!' || x[i] == '?')
{
sc += 1;
}
}
return sc;
}
I would expect that the values in the array would repeat in every 3rd character but I do not understand why to out put are different if they are referencing the same index.
Input:
Command line argument: baz
User input: barfoo
Output: caqmut
Expected output: caqgon
Values of key_number[] after first for loop:
key_number[0] = 1
key_number[1] = 0
key_number[2] = 25
key_number[3] = 32767
key_number[4] = 32
key_number[5] = 57
Code used:
#include <cs50.h>
#include <stdio.h>
#include <string.h>
#include <ctype.h>
int main(int argc, string argv[])
{
if(argc<=1)
{
printf("Usage: ./vigenere k");
exit(1);
}
// convert command line input from string to int varible keyword
string keyword = argv[1];
//prompt user input and initialized
printf("plaintext: ");
string plaintext = get_string();
printf("ciphertext: ");
//create lower_case_array
char lower_case[26] = "abcdefghijklmnopqrstuvwxyz";
//create upper_case_array
char upper_case[26] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
//convert key from string to int[]
//int array_length =strlen(plaintext);
int key_number[6]; // [array_length]
int key_length = strlen(keyword);
//loop though key_number for the length of plaintext
for (int i = 0; i < (strlen(plaintext)); i++)
{
//if char is uppercase
if (keyword[i] >= 65 && keyword[i] < 91 )
{
key_number[i] = (keyword[i % key_length]) - 65;
}
// if char is lowercase
else if (keyword[i] >= 97 && keyword[i] < 123)
{
key_number[i] = (keyword[i % key_length]) - 97;
}
}
//print out letters accoring to ceasar cryptography
for (int i = 0; i < strlen(plaintext); i++)
{
//branch if letter is upper case
if (plaintext[i] >= 65 && plaintext[i] < 91 )
{
printf("%c", upper_case[((plaintext[i] - 65 + key_number[i]) % 26)]);
}
//branch if letter is lower case
else if (plaintext[i] >= 97 && plaintext[i] < 123)
{
printf("%c", lower_case[((plaintext[i] - 97 + key_number[i]) % 26)]);
}
//branch if any other character
else
{
printf("%c", plaintext[i]);
}
}
printf("\n");
}
what puzzled me when I read your code is that you're using keyword[i % key_length] sometimes and sometimes keyword[i].
So when you're using i, you can go past the keyword table: undefined behaviour because plaintext is probably longer than keyword
You could have avoided that by rewriting your code more cleanly:
for (int i = 0; i < (strlen(plaintext)); i++)
{
char kc = keyword[i % key_length];
//if char is uppercase
if (kc >= 'A' && kc <= 'Z' ) // aka isupper(kc)
{
key_number[i] = kc - 'A';
}
// if char is lowercase
else if (kc >= 'a' && kc <= 'z') // aka islower(kc)
{
key_number[i] = kc - 'a';
}
}