p13.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdbool.h>
#include "intcode.h"

#define WIDTH 50
#define HEIGHT 30
#define MAX_NUM_OUTPUTS 5000

size_t blocks_remaining(int8_t *grid) {
    size_t b = 0;
    for (size_t x = 0; x < WIDTH*HEIGHT; x++) if (grid[x] == 2) b++;
    return b;
}

int main(int argc, char **argv) {
    int64_t output[MAX_NUM_OUTPUTS];
    size_t length;
    int64_t *source = load_source_code_from_file(argv[1], &length, 10000);
    int8_t *grid = (int8_t *)calloc(WIDTH*HEIGHT, 1);
//    int64_t min_x = INT64_MAX;
//    int64_t max_x = INT64_MIN;
//    int64_t min_y = INT64_MAX;
//    int64_t max_y = INT64_MIN;
    bool done = false;
    struct program *p = init_program_instance(source, length, output);
    p->input = NULL;
    p->remaining_inputs = 0;
    
    while (!done) {
        done = run_program_instance_until_halted(p);
        for (int64_t i = 0; i < p->num_outputs; i += 3) {
            int64_t x = output[i];
            int64_t y = output[i+1];
            grid[x+y*WIDTH] = output[i+2];
//            if (max_x < x) max_x = x;
//            if (min_y > y) min_y = y;
//            if (min_x > x) min_x = x;
//            if (max_y < y) max_y = y;
        }
    }
    printf("Pt 1: %zu\n", blocks_remaining(grid));
    free_program_instance(p);

//    printf("x: (%lld to %lld)\nY: (%lld to %lld)\n", min_x, max_x, min_y, max_y);
//    for (int64_t y = min_y; y < max_y; y++) {
//        for (int64_t x = min_x; x < max_x; x++) {
//            int8_t g = grid[y*WIDTH + x];
//            switch(g) {
//                case 0: printf(" "); break;
//                case 1: printf("#"); break;
//                case 2: printf("@"); break;
//                case 3: printf("-"); break;
//                case 4: printf("o"); break;
//            }
//        }
//        printf("\n");
//    }
    
    p = init_program_instance(source, length, output);
    p->code[0] = 2; // Free play!!!!
    int64_t input = 0;
    p->input = &input;
    p->remaining_inputs = 1;
    done = false;
#define UNKNOWN (-100111011)
    int64_t score = 0;
    int64_t ball_x = UNKNOWN;
    int64_t ball_y = UNKNOWN;
    int64_t paddle_x = 0;
    int64_t paddle_y = 0;
    while (!done) {
        done = run_program_instance_until_halted(p);
        for (int64_t i = 0; i < p->num_outputs; i += 3) {
            int64_t x = output[i];
            int64_t y = output[i+1];
            if (x == -1 && y == 0) {
                score = output[i+2];
            } else {
                grid[x+y*WIDTH] = output[i+2];
            }
            
            if (output[i+2] == 3) {
                paddle_x = x;
                paddle_y = y;
            } else if (output[i+2] == 4) {
                ball_y = y;
                ball_x = x;
            }
        }
        if (paddle_x > ball_x) {
            input = -1;
        } else if (paddle_x < ball_x) {
            input = 1;
        } else {
            input = 0;
        }
        p->input = &input;
        p->remaining_inputs = 1;

        if (blocks_remaining(grid) == 0) {
            done = true;
            printf("Pt 2: %lld\n", score);
        }
        
    }

    free_program_instance(p);
    free(grid);
    free(source);
    return 0;
}