在 C 中递归连接字符串

Question

I need help to concatenate strings using recursion in C.

I have 2 strings in input, src and dest , and I need to concatenate recursively src to dest , and store the concatenated string in dest .

eg if src="house" and dest="clock" , the output should be "chlooucske" .

EDIT: This is my code:

char* str_concatenate(char dest[], char src[], int index){
    char temp[256]; // temporaty variable
    temp[index]=src[index]; //should copy each letter from src to temp
    temp[index+1]=dest[index]; //should copy each letter from dest to temp
    dest[index]=temp[index]; //should store the concatenated string into dest
    if (src[index]=='\0'){ //base case
        return dest;
    }
    else
        return str_concatenate(dest,src,index+1);
}

int main(){ //test
        char dest[]="house";
        char src[]="clock";

        char* ris=str_concatenate(dest,src,0);

        printf("dest= %s\n", ris); //should print "chlooucske" 
    return 0;
    }

However it copies the entire word from src to dest and prints it, it does not concatenate letters.

Answer 1

The destination pointer is pointing to a string constant. You are trying to modify it and it causes your program to crash. You can use an array and initialize it as the destination string.

You may want to take a look at this. This explains your problem. What is the difference between char s[] and char *s?