<Codesignal> Decipher

Easy

Consider the following ciphering algorithm:

• For each character replace it with its code.
• Concatenate all of the obtained numbers.

Given a ciphered string, return the initial one if it is known that it consists only of lowercase letters.

Note: here the character's code means its decimal ASCII code, the numerical representation of a character used by most modern programming languages.

Example

For cipher = "10197115121", the output should be
decipher(cipher) = "easy".

Explanation: charCode('e') = 101, charCode('a') = 97, charCode('s') = 115 and charCode('y') = 121.

Input/Output

• [execution time limit] 0.5 seconds (c)

• [input] string cipher

  A non-empty string which is guaranteed to be a cipher for some other string of lowercase letters.

  Guaranteed constraints:
  2 ≤ cipher.length ≤ 100.

• [output] string

[C] Syntax Tips

// Prints help message to the console
// Returns a string
char * helloWorld(char * name) {
    char * answer = malloc(strlen(name) + 8);
    printf("This prints to the console when you Run Tests");
    strcpy(answer, "Hello, ");
    strcat(answer, name);
    return answer;
}

---

Solution

char *decipher(char *cipher)
{
	char *string=calloc(51,sizeof(char));
	int temp=0, count=0;

	for(int i=0;i<strlen(cipher);i++)
	{
		temp*=10;
		temp+=cipher[i]-'0';

		if(temp>='a' && temp<='z')
		{
			string[count++]=temp;
			temp=0;
		}
	}

	return string;
}