For c and c++ try this-

Create a file named input.txt in the same folder as your solution program(.c or .cpp file) is in.
Then modify your code this way-

// your include statemnts
#include<time.h>
#include<stdio.h>

int main()
{
    freopen("input.txt","r",stdin);
    double start=clock();
    /*

        your solution code here

    */
    double end=clock();
    printf("\n\nTotal runtime = %lf ms",(end-start)*1000/CLOCKS_PER_SEC);
    return 0;
}

Now compile and run the program.

# Don't forget to remove the freopen(...) statement before submitting your code