flight.c

flight.c

// Roy Howie
// flight.c

#include <ctype.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define MIN_LOWER_BOUND 0
#define MAX_LOWER_BOUND 80
#define MAX_UPPER_BOUND 120
#define DELIM " "

typedef char String[256];
typedef enum { false, true } bool;

void    getData     (char *, char *, void *, int, int, char *);
bool    isBetween   (int, int, float);
void    parseLine   (char *, int *, float *);

int main (void) {
    FILE * data;
    String fileName, currentLine;
    int lowest = 0, highest = 120;
    // tracks for each month [ daysTotal, daysInRange ]
    int tracker[][2] = {{0, 0}, {0, 0}, {0, 0}, {0, 0}, {0, 0}, {0, 0},
                        {0, 0}, {0, 0}, {0, 0}, {0, 0}, {0, 0}, {0, 0}};
    int greatestMonth = -1;
    float greatestMonthValue = -1.0;

    printf("Tell me about your dragon’s preferred temperature for flying:\n");

    getData("What is the coldest temperature they can fly in?\n", "%d",
        &lowest, MIN_LOWER_BOUND, MAX_LOWER_BOUND, "lower bound");
    getData("What is the hottest temperature they can fly in?\n", "%d",
        &highest, lowest, MAX_UPPER_BOUND, "upper bound");

    printf("Please enter the name of the weather data file for Dragon Island.\n");
    scanf("%s", fileName);

    if ((data = fopen(fileName, "r")) == NULL) {
        printf("File could not be opened. Exiting.\n");
        return -1;
    }

    while (fgets(currentLine, 256, data) != NULL) {
        int month;
        float temp;

        parseLine(currentLine, &month, &temp);

        // if month is -1, break since we've reached EOF
        if (month == -1) break;

        // if the temperature for the current line is in the desired range
        if (isBetween(lowest, highest, temp))
            // incremenet the appropriate tracker by 1
            tracker[month - 1][1]++;
        // always increment day count by 1
        tracker[month - 1][0]++;
    }

    for (int i = 0; i < 12; i++) {
        float percent = 100.0 * tracker[i][1] / tracker[i][0];
        printf("Month %d: %2.1f percent of days in range.\n", i + 1, percent);

        // if this month was better than our current best, record it
        if (percent > greatestMonthValue) {
            greatestMonth = i + 1;
        }
    }

    printf("I recommend month %d for the Celebration of the First Flight!\n", greatestMonth);

    if (fclose(data) == EOF) {
        perror("Unable to close file. Exiting program.");
        return -1;
    }

    return 0;
}

void getData (char * msg, char * scanType, void * address, int lowest, int highest, char * boundType) {
    String temp;

    printf("%s", msg);
    scanf(scanType, address);

    while (!isBetween(lowest, highest, * (int *) address)) {
        sprintf(temp, "Not a valid %s. Must be between %d and %d! Enter a new value:\n", boundType, lowest, highest);
        printf("%s", temp);
        scanf(scanType, address);
    }
}

bool isBetween (int min, int max, float n) {
    return min <= n && n <= max;
}

void parseLine (char * line, int * month, float * temp) {
    char * token;
    int step = 0;

    while ((token = strsep(&line, DELIM)) != NULL) {
        if (!isdigit(*token)) continue;

        switch (step++) {
        case 0:
            *month = atoi(token);
            if (*month == -1) return;
            break;
        case 3:
            *temp = atof(token);
            return;
        }
    }
}