cs50 pset3 binary search

Question

im not sure if my binary search code is correct, when I try to compile it I get the following message:

/usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_info): relocation 0 has invalid symbol index 11 /usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_info): relocation 1 has invalid symbol index 12 /usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_info): relocation 2 has invalid symbol index 2 /usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_info): relocation 3 has invalid symbol index 2 /usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_info): relocation 4 has invalid symbol index 11 /usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_info): relocation 5 has invalid symbol index 13 /usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_info): relocation 6 has invalid symbol index 13 /usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_info): relocation 7 has invalid symbol index 13 /usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_info): relocation 8 has invalid symbol index 12 /usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_info): relocation 9 has invalid symbol index 13 /usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_info): relocation 10 has invalid symbol index 13 /usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_info): relocation 11 has invalid symbol index 13 /usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_info): relocation 12 has invalid symbol index 13 /usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_info): relocation 13 has invalid symbol index 13 /usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_info): relocation 14 has invalid symbol index 13 /usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_info): relocation 15 has invalid symbol index 13 /usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_info): relocation 16 has invalid symbol index 13 /usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_info): relocation 17 has invalid symbol index 13 /usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_info): relocation 18 has invalid symbol index 13 /usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_info): relocation 19 has invalid symbol index 21 /usr/bin/ld: /usr/lib/debug/usr/lib/x86_64-linux-gnu/crt1.o(.debug_line): relocation 0 has invalid symbol index 2 /usr/bin/../lib/gcc/x86_64-linux-gnu/4.8/../../../x86_64-linux-gnu/crt1.o: In function _start': (.text+0x20): undefined reference tomain' clang: error: linker command failed with exit code 1 (use -v to see invocation) make: *** [helpers] Error 1

my code is below:

#include <cs50.h>
#include <stdio.h>
#include <string.h>

#include "helpers.h"


/**
* Returns true if value is in array of n values, else false.
*/



bool search(int value, int values[], int n)
{

if (n < 0)
    {
        printf("n must be a non-negative integer\n");
        return false;
    }

else
    {
            for (int i = 0; i < n; i++)

            {
                int middlevalue = values[n/2];
                printf("Middle value is %d\n", middlevalue);
             if (middlevalue == value)
                {
                     printf("Number is found!\n");
                     return true;
                }

            }
    }


            int middlevalue = values[n/2];
            if (value > middlevalue)
                        {

                         for (int i = 0; (values[n/2] < i < n) ; i++)
                            {
                            if (i == value)

                                {
                                printf("Number is found!\n");
                                return true;
                                }
                            }
                        }

                    else if (value < middlevalue)
                        {
                            for (int i = 0; (0 < i < values[n/2]) ; i++)
                            {
                            if (i == value)

                                {
                                printf("Number is found!\n");
                                return true;
                                }
                            }

                        }

                else 
                {
                    printf("Number cannot be found!\n");
                }

return false;
}

if you could look it over that would be great, thank you!

Answer 1

You are getting this error message because, apparently the compiler couldn't find the main function in your program. Most probably you are compiling your code like this:

make helpers

the compiler does not find any main function in you program as a result it yells at you with this extremely long error message. Instead you should compile your code with:

make find

this will compile the program which looks for a specific number in the list

make generate 

this will compile the program that will generate random numbers