How to calculate string length without using string function and Loop in c?

Question

Consider an implementation of Strings consisting of an array where the first element of the array indicates the length of the String and the next elements represent the value of the ASCII characters in the String.
Implement String concatenation of such scenario using C?

Answer 1

#include<stdio.h>
main()
{
        char str[100];
        printf("Enter a string\n");
        scanf("%[^\n]",str);
        int i=0;
        for(;str[i];i++);
        printf("Length is %d\n",i);
}

Answer 2

//Lets check the below program

include <stdio.h>   
int main()
{
  char str[100];
  printf("Enter a string: ");
  printf( "\rLength is: %d", printf("Entered string is: %s\n", gets(str)) - 20);
  return 0;
}