将字符串中的一个字母复制到另一个字母中

Question

So I need to create a function that copies the characters from the even position of one string into a dynamically create new string and then return the new string. If I send the function "ABCDEFG" it returns "ACEG". How do you copy one character of a string into a new one in C? I tried the strcpy function, but it just printed the whole string.

    char * str(char *s1){
    int i;
    char *s2;
    s2 = (char *)malloc(sizeof(char ));
    for(i = 0; i < strlen(s1); i++){
        if(i % 2 == 0){
            ///copy from s1 to s2
            printf("s2: %s", s2);   
        }
    }
    return s2;
    }

Answer 1

Use strcat() function available in C. You don't need to copy char from s1 to s2 instead append the required characters as string from s1 to string s2. This is enough hint to solve your issue.