#include <stdlib.h>

#include <stdio.h>

#include <string.h>

// char *gcvt(double number, size_t ndigits, char *buf);

int main() {

char ptr[20];

double a = 100;

gcvt(a, 10, ptr);

int length = strlen(ptr);

printf("%s length = %d\n", ptr, length);

return 0;

}