Counting how many letters are repeated in a string

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python count letters in word

My program should first read an entered string word and then count the amount of repeated letters.

For example, if I enter apple it should print 1, but instead it prints 4.

I suppose word[i] = word[i + 1] isn't the right way to count?

#include<stdio.h>

int main() {

    int i, j, wordLength = 0, alphabeticalSort, counter = 0, swap;
    char word[51];

    scanf("%s", word);

    while (word[wordLength] != '\0'){
        wordLength++;
    }

    ...

    for (i = 0; i < wordLength; i++){
        if (word[i] = word[i + 1])
            counter++;
    }

    printf("\nNumber of repeated letters: %d", counter);

    ...

    return 0;
}

It's best to split what you're doing into two functions, one of which will count the number of occurrences of each letter.

#define LETTERS 26

/* counts number of occurrences of each lowercase letter in str. Result is placed in outCounts, 
   assuming it has room */
void countletters(char *str, int outCounts[])
{
    memset(outCounts, 0, LETTERS * sizeof (int));

    for (; *str; ++str) {
        if (isupper(*str))
            *str = tolower(str);
        if (islower(*str))
            ++outCounts[*str - 'a'];
    }
}

Then you write another function will examines the outCounts array, which is modified. If a letter is repeated, the corresponding member of this array will be greater than one. I leave this as an exercise to the reader.

Python, This particular operation on string is quite useful in many applications such as removing duplicates or detecting unwanted characters. Method #1 : Naive method. Given an integer N and a lowercase string. The string is repeated infinitely. The task is to find the No. of occurrences of a given character x in first N letters. Examples: Input : N = 10 str = "abcac" Output : 4 Explanation: "abcacabcac" is the substring from the infinitely repeated string. In first 10 letters 'a' occurs 4 times.

You have:

for (i = 0; i < wordLength; i++){
    if (word[i] = word[i + 1])
        counter++;
}

Look at the 'comparison' inside the loop; you're giving the value of word[i+1] to word[i+1]. This condition will always be true unless the word[i+1]'s value is a 0 or a null char which is also a 0 in the ASCII table.

Remember: the equality operator in C is always ==, so replace the = with ==.

Counting repeated characters in a string in Python, My first idea was to do this: chars = "abcdefghijklmnopqrstuvwxyz" check_string = "i am checking this string to see how many times each character appears" for  In this article, we will count and print number of repeated character occurrences in a String i.e.; From a given String, we will be counting & printing. Number of repeated character occurrences; Along with its count . Steps for counting repeated character occurrences: Create empty HashMap of type Character & Integer

int main()
{
    char string[80];
    int c = 0, count[26] = {0}, x;

    printf("Enter a string\n");
    //gets(string); 
    scanf("%s", string); 
    while (string[c] != '\0') {

       if (string[c] >= 'a' && string[c] <= 'z') {
          x = string[c] - 'a';
          count[x]++;
       }

       c++;
    }

    for (c = 0; c < 26; c++)
       printf("%c occurs %d times in the string.\n", c + 'a', count[c]);

    return 0;
}

How to count the number of repeated characters in a string in Python, Counting repeated characters in a string maps each unique character with the and add any key-value pairs with a frequency value greater than 1 to repeated . Python | Count occurrences of a character in string Given a string, the task is to count the frequency of a single character in that string. This particular operation on string is quite useful in many applications such as removing duplicates or detecting unwanted characters.

Python: Count repeated characters in a string, Python Exercises, Practice and Solution: Write apython program to count repeated characters in a string. This video tells how to count how many times each character in string is repeated.

How to count how many times does a letter in my string occured in , How do you count the number of times words appear in strings (Python)?. 1,331 Views for i in range(j+1,len(s),1): # forward loop to count character repetition. C program to find the frequency of characters in a string: This program counts the frequency of characters in a string, i.e., which character is present how many times in the string. For example, in the string "code" each of the characters 'c,' 'd,' 'e,' and 'o' has occurred one time.

Python program to find all duplicate characters in a string, Writing programs without using any modules. We can First, we will find the duplicate characters of a string using the count method. Let's see  I count letters in a string (can be any string), using a for loop to iterate through each letter. The problem is that this method is very slow and I want to avoid loops. Any ideas? I thought that maybe if I remove checked letters from the string after each loop, then in some cases, where many letters repeat, that would make a difference.

Comments
  • if (word[i] = word[i + 1]) should be if (word[i] == word[i + 1]). Also, consider including string.h and using strlen() instead of manually counting the length. These common functions exist for a reason.
  • Since it produces the wrong answer, what you've got clearly isn't what's needed. You need to count the number of occurrences of each letter (does 'Abracadabra' count 'A' and 'a' separately). Then you need to count the number of letters that have more than 1 occurrence.
  • Thanks guys. Also, is including string.h necessary when using strlen, strcmp, etc? I've used them in the past, but never included the string.h library.
  • Are you counting repeated adjacent letters, or repeated occurrences of a letter anywhere in the word (string)? It matters because 'abracadabra' has no adjacent repeats, but it repeats a, b, and r non-adjacently. So, it's count might be 0 or 3, depending on this detail in the specification.
  • You really don't need the wordLength loop; you could simply modify your for loop to use: for (int i = 0; word[i] != '\0'; i++) to control it. If you must have wordLength, then use wordLength = strlen(word); instead of your loop. Yes, strlen() returns the length of a string.
  • No! Never use gets
  • See Why the gets() function is too dangerous to be used — ever!
  • thank you for your suggestions :)
  • You assume that all the characters in the string are lower-case alphabetic; I'm not convinced that's a safe assumption. I think you'd do better to ignore spaces and punctuation and digits (or non-alphabetic characters). Maybe map upper-case to lower-case and convert appropriately, or maybe count them separately; it isn't clear from the question which is expected.
  • Ah. scanf. No better, is it?.