CODEWITHSUNDEEP
crecursion
PIG443
PIG443

Reputation: 91

Clearfying an index in a recursion function c

Is it possible to set an index inside a recursion without sending a null parameter?

example:

void checkArry(char str[],int len){
    if(str[index] == 'P')
        printf("P");
    if(index != len)
        checkArry(str,len);

}

How can I set that index to start from 0 and keep adding 1 to it without it being initialized each run?

Upvotes: 1

Views: 77

Answers (1)

dreamcrash
dreamcrash

Reputation: 51423

Pass the index as parameter, and increment for each recursive call:

void checkArry(char str[],int len, int index){
    if(str[index] == 'P')
        printf("P");
    if(index != len)
        checkArry(str,len, index + 1);

}

and called with checkArry(str, len, 0);

If you do not want to add the extra index parameter, just use the len variable instead, and go through the array in reverse:

void checkArry(char str[],int len){
    if(len >= 0){
       if(str[len] == 'P')
          printf("P");
       checkArry(str, len - 1);
    }
}

Make sure you call the function correctly

checkArry(str, strlen(str) - 1);

We should start by the last character, hence strlen(str) - 1.

If for some reason you do not want to print in reverse, then you can use this version, which will print from 0 to length:

void checkArry(char str[],int len){
    if(len >= 0){
       checkArry(str, len - 1);
       if(str[len] == 'P')
          printf("P");
    }
}

Upvotes: 1

Related Questions