Changing letters in C

Question

I have a question, I’m making an algorithm that takes the phrase of the user that has no meaning, as if it were a code, to solve has a key that is the letters that most comes out of the Portuguese alphabet, To solve I have to associate each letter of the text with the letter that most used in English, EX c =a, z=o and so on, I made the code only that it does not change is always the same letter that the user typed. could someone give me some tips. `#include

#include <string.h>
main()
{
    char chave[20],texto[20],frase[20];
    int size,i;
    printf("Digite o texto para ser alterado: ");
    scanf("%s",chave);
    size=strlen(chave);
    strcpy(texto,chave);  
    for(i=0;i<size;i++)
    {
        if (frase[i]=='c')
            frase[i]='a';
        else if (texto[i]=='b')
            frase[i]='s';
        else if (texto[i]=='d')
            frase[i]='e';
        else if (texto[i]=='e')
            frase[i]='d';
    } 
    printf("Texto original:\n%s\n Novo texto:\n%s\n",chave,texto);  
}

Answer 1

I found some errors in your like, for example, if (frase[i]=='c') frase[i]='a'; and if I’m not mistaken you wanted so if (texto[i]=='c') frase[i]='a';

I changed a few more things in your code and it’s working.

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
main()
{
    char chave[20], texto[20], frase[20];
    int size,i;

    printf("Digite o texto para ser alterado: ");
    scanf("%s",chave);

    size=strlen(chave);
    strcpy(texto, chave);  

    for(i=0;i<size;i++)
    {
        if (texto[i]=='c')
            frase[i]='a';
        else if (texto[i]=='b')
            frase[i]='s';
        else if (texto[i]=='d')
            frase[i]='e';
        else if (texto[i]=='e')
            frase[i]='d';
        else frase[i]=texto[i];
    } 
    printf("Texto original:\n %s\nNovo texto:\n %s\n", chave, frase);  
}