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

// The amount of input lines
const int lines = 1000;

// The amount of numbers that can be found
const int number_size = 10;

const char numbers[10][6] =
    { "zero"
    , "one"
    , "two"
    , "three"
    , "four"
    , "five"
    , "six"
    , "seven"
    , "eight"
    , "nine"
    };

int  extract_number(int *numbers, int size);
int *find_numbers(char *text);
int  numbers_size(int *numbers);
int  starts_with_number(char *text);

int main(void) {
    int sum = 0;

    for (int i = 0; i < lines; i++) {
        // Instead of directly looping through the array,
        // we extract a list of integers first
        int *ns = find_numbers(get_string(""));

        // Then use that list to increase the sum
        sum += extract_number(ns, numbers_size(ns));

        // Free all allocated information
        free(ns);
    }

    printf("%i\n", sum);
    return 0;
}

/* Given a list of integers, combines the first and the last digit to create a
single number between 0 and 100.
*/
int extract_number(int *numbers, int size) {
    return (numbers[0] * 10) + numbers[size - 1];
}

// Convert a string to an array of integers
int *find_numbers(char *text) {
    int length = strlen(text);

    int *items = malloc(sizeof(int) * length);
    int cursor = 0;

    for (int i = 0; i < length; i++) {
        char c = text[i];

        if (c >= '0' && c <= '9') {
            items[cursor] = c - '0';
            cursor++;
        }
        else {
            int n = starts_with_number(text + i);

            if (n >= 0) {
                items[cursor] = n;
                cursor++;
            }
        }
    }

    items[cursor] = -1;

    return items;
}

int numbers_size(int *numbers) {
    int i = 0;

    while (numbers[i] >= 0) {
        i++;
    }

    return i;
}

/* Determine whether a (sub)string starts with a given number.
*/
int starts_with_number(char *text) {
    for (int i = 0; i < number_size; i ++) {
        if (strstr(text, numbers[i]) == text) {
            return i;
        }
    }

    // If not, return -1
    return -1;
}