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Day 16 solutions

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Peter 2021-12-17 00:18:53 +08:00
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#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <stdbool.h>
// SAMPLE INPUT
#define INPUT "9C0141080250320F1802104A08"
#define TYPE_LITERAL(t) ((t) == 4)
#define HEADER_LEN 6
#define BIT_TYPE_LEN 15
#define PACKET_TYPE_LEN 11
#define BLOCK_LEN 5
#define DIGIT_LEN 4
typedef long int INTEGER;
char *BIN_MAP[] = {
"0000",
"0001",
"0010",
"0011",
"0100",
"0101",
"0110",
"0111",
"1000",
"1001",
"1010",
"1011",
"1100",
"1101",
"1110",
"1111",
};
typedef struct
{
int packets;
int bits;
INTEGER value;
int version_total;
} COUNTER;
char *hex2bin(char *hex)
{
char *bin = calloc(strlen(hex) * DIGIT_LEN, sizeof(char));
char *bin_ = bin;
for (char *c = hex; *c != '\0'; c++)
{
if (*c >= '0' && *c <= '9')
strcpy(bin_, BIN_MAP[*c - '0']);
else
strcpy(bin_, BIN_MAP[*c - 'A' + 10]);
bin_ += DIGIT_LEN;
}
return bin;
}
COUNTER *read_literal(char *bin_literal)
{
COUNTER *ctr = calloc(1, sizeof(COUNTER));
char value_buf[BUFSIZ] = {0};
bool end_of_block = false;
for (int i = 0;; i++)
{
memcpy(&value_buf[i * DIGIT_LEN], &bin_literal[ctr->bits + 1], DIGIT_LEN);
if (bin_literal[ctr->bits] == '0')
end_of_block = true;
ctr->bits += BLOCK_LEN;
if (end_of_block)
break;
}
ctr->value = strtol(value_buf, NULL, 2);
return ctr;
}
COUNTER *read_header(char *bin)
{
COUNTER *ctr = calloc(1, sizeof(COUNTER));
ctr->bits = HEADER_LEN;
INTEGER values[BUFSIZ] = {0};
int value_count = 0;
char buf[3];
memcpy(buf, &bin[0], 3);
int version = strtol(buf, NULL, 2);
memcpy(buf, &bin[3], 3);
int type = strtol(buf, NULL, 2);
ctr->version_total += version;
if (TYPE_LITERAL(type))
{
COUNTER *ctr_ = read_literal(bin + HEADER_LEN);
ctr->bits += ctr_->bits;
ctr->value = ctr_->value;
ctr->packets++;
free(ctr_);
return ctr;
}
ctr->packets++;
// READ PACKETS
if (bin[6] == '0') // 15 BIT NUMBER
{
char value_buf[BIT_TYPE_LEN];
ctr->bits += BIT_TYPE_LEN + 1;
memcpy(value_buf, &bin[HEADER_LEN + 1], BIT_TYPE_LEN);
int max_bits = (int)strtol(value_buf, NULL, 2);
// printf("TOTAL_LEN %d %s\n", max_bits, value_buf);
bin += HEADER_LEN + BIT_TYPE_LEN + 1;
int bits = 0;
while (bits < max_bits)
{
COUNTER *ctr_ = read_header(bin);
ctr->bits += ctr_->bits;
bin += ctr_->bits;
bits += ctr_->bits;
ctr->version_total += ctr_->version_total;
values[value_count] = ctr_->value;
value_count++;
free(ctr_);
}
}
else
{ // 11 BIT NUMBER
char value_buf[PACKET_TYPE_LEN];
ctr->bits += PACKET_TYPE_LEN + 1;
memcpy(value_buf, &bin[HEADER_LEN + 1], PACKET_TYPE_LEN);
int max_packets = (int)strtol(value_buf, NULL, 2);
// printf("TOTAL_PACKETS %d %s\n", max_packets, value_buf);
int count = 0;
bin += HEADER_LEN + PACKET_TYPE_LEN + 1;
while (count < max_packets)
{
COUNTER *ctr_ = read_header(bin);
ctr->bits += ctr_->bits;
bin += ctr_->bits;
count += ctr_->packets;
ctr->version_total += ctr_->version_total;
values[value_count] = ctr_->value;
value_count++;
free(ctr_);
}
}
switch (type)
{
case 0: // SUM
for (int i = 0; i < value_count; i++)
ctr->value += values[i];
break;
case 1: // PROD
ctr->value = values[0];
for (int i = 1; i < value_count; i++)
ctr->value *= values[i];
break;
case 2: // MIN
ctr->value = values[0];
for (int i = 1; i < value_count; i++)
if (values[i] < ctr->value)
ctr->value = values[i];
break;
case 3: // MAX
ctr->value = values[0];
for (int i = 1; i < value_count; i++)
if (values[i] > ctr->value)
ctr->value = values[i];
break;
case 5: // GT
ctr->value = values[0] > values[1];
break;
case 6: // LT
ctr->value = values[0] < values[1];
break;
case 7: // EQ
ctr->value = values[0] == values[1];
break;
default:
printf("ERROR\n");
}
return ctr;
}
int main(int argc, char const *argv[])
{
char hex_string[] = INPUT "\0";
char *bin = hex2bin(hex_string);
COUNTER *ctr = read_header(bin);
printf("VERSION_TOTAL %d VALUE %li\n", ctr->version_total, ctr->value);
return 0;
}