Analysis: Your Ride Is Here

This is probably the easiest problem in the entire set of lessons. An `ad hoc' problem, no particular algorithms or tricks are needed save one: one must be careful to get all 72 characters of input without processing the newline on the end!

Here is a prototype solution:

#include <stdio.h>
#include <ctype.h>

int
hash(char *s)
...{
    int i, h;

    h = 1;
    for(i=0; s[i] && isalpha(s[i]); i++)
        h = ((s[i]-'A'+1)*h) % 47;
    return h;
}

void
main(void)
...{
    FILE *in, *out;
    char comet[100], group[100];  /**//* bigger than necessary, room for newline */

    in = fopen("input.txt", "r");
    out = fopen("output.txt", "w");

    fgets(comet, sizeof comet, in);
    fgets(group, sizeof group, in);

    if(hash(comet) == hash(group))
        fprintf(out, "GO ");
    else
        fprintf(out, "STAY ");
    exit (0);
}

 

 Solutions generally run in under 0.01 seconds.