advent-of-code/2022/day11/main.c

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

typedef struct Monkey_ Monkey;

typedef struct Monkey_ {
    long long item[64];
    int items, is_multiply, opertant_is_old, operant, test, test_true, test_false, inspections;
} Monkey;

Monkey* newMonkey() 
{
    char *line = NULL;
    size_t size;
    size_t len;
    Monkey *monkey = malloc(sizeof(Monkey));
    monkey->inspections = 0;
    // items
    len = getline(&line, &size, stdin);

    char *begin = line+18;
    char *token = NULL;
    for (int j = 0; (token = strsep(&begin, ",")); j++) 
    {
        // printf("%u: %s\n", j, token);
        monkey->item[j] = atoi(token);
        monkey->items = j+1;
    }

    // operation
    len = getline(&line, &size, stdin);
    monkey->is_multiply = line[23] == '*';
    monkey->opertant_is_old = line[25] == 'o';
    if (!monkey->opertant_is_old)
    {
        monkey->operant = atoi(line+25);
    }

    // test
    len = getline(&line, &size, stdin);
    monkey->test = atoi(line+21);

    // test true
    len = getline(&line, &size, stdin);
    monkey->test_true = atoi(line+29);

    // test true
    len = getline(&line, &size, stdin);
    monkey->test_false = atoi(line+30);

    len = getline(&line, &size, stdin);
    return monkey;
}

void inspect(Monkey *monkey, Monkey *monkeys[])
{
    monkey->inspections += monkey->items;
    for (int i = 0; i < monkey->items; i++)
    {
        // set operant
        int operant = monkey->operant;
        if (monkey->opertant_is_old)
            operant = monkey->item[i];

        // set operation
        if (monkey->is_multiply) 
        {
            monkey->item[i] *= operant;
        } else {
            monkey->item[i] += operant;
        }

        monkey->item[i] /= 3;

        // throw item based on test
        int throw = monkey->test_true;
        if (monkey->item[i] % monkey->test != 0)
        {
            throw = monkey->test_false;
        }

        monkeys[throw]->item[monkeys[throw]->items] = monkey->item[i];
        monkeys[throw]->items++;
    }
    monkey->items = 0;
}

int main()
{

    int monkeys = 0;
    Monkey *monkey[10] = { };

    char *line = NULL;
    size_t size;
    size_t len;
    int active1 = 0, active2 = 0;

    while ((len = getline(&line, &size, stdin)) != -1)
    {
        // create monkeys
        Monkey *new = newMonkey();
        monkey[monkeys] = new;
        monkeys++;
        
        // print monkey attributes
        printf("Items:");
        for (int i = 0; i < new->items; i++)
        {
            printf("%lldd ", new->item[i]);
        }
        printf("\n %d %d %d %d %d %d\n\n",
            new->is_multiply,
            new->opertant_is_old,
            new->operant,
            new->test,
            new->test_true,
            new->test_false
                );
    }

    for (int i = 0; i < 20; i++)
    {
        // do inspection
        for (int ii = 0; ii < monkeys; ii++)
        {
            inspect(monkey[ii], monkey);
        }
        
        // output rounds
        printf("Round %d\n", i);
        for (int ii = 0; ii < monkeys; ii++)
        {
            printf("Monkey %d: ", ii);
            for (int iii = 0; iii < monkey[ii]->items; iii++)
            {
                printf("%lld ", monkey[ii]->item[iii]);
            }
            printf("\n");
        }
    }
    
    // get two most active monkeys
    for (int i = 0; i < monkeys; i++)
    {
        if (monkey[i]->inspections > active1) 
        {
            active2 = active1;
            active1 = monkey[i]->inspections;
        }
        printf("Monkey %d inspected items %d times. \n", i, monkey[i]->inspections);
    }

    printf("Monkey biz: \n%d\n", active1 * active2);
}