From 181ce8379fef07795fbb710489df2e29cbaf96b5 Mon Sep 17 00:00:00 2001
From: Peter <peterr.00000@gmail.com>
Date: Fri, 24 Dec 2021 17:02:31 +0800
Subject: [PATCH] Attempt at 24 (Bad time complexity - could be done manually)

---
 24/24-1.c | 170 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 170 insertions(+)
 create mode 100644 24/24-1.c

diff --git a/24/24-1.c b/24/24-1.c
new file mode 100644
index 0000000..8a927fa
--- /dev/null
+++ b/24/24-1.c
@@ -0,0 +1,170 @@
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <ctype.h>
+
+#define PROGRAM_SIZE 512
+
+typedef enum
+{
+    INP = 0,
+    ADD,
+    MUL,
+    DIV,
+    MOD,
+    EQL,
+
+    SUB,
+} OPCODE;
+
+const OPCODE INVERSE[] = {
+    INP,
+    SUB,
+    DIV,
+    MUL,
+    MOD, //
+    EQL,
+};
+
+const char *OPCODE_STRINGS[] = {
+    "inp",
+    "add",
+    "mul",
+    "div",
+    "mod",
+    "eql",
+};
+
+OPCODE str2opcode(char *str)
+{
+    int i = 0;
+    while (strcmp(str, OPCODE_STRINGS[i]) != 0)
+        i++;
+    return i;
+}
+
+typedef long int NUMBER;
+
+typedef enum
+{
+    UNDEFINED = 0,
+    LITERAL,
+    VARIABLE,
+} VALUE_TYPE;
+
+typedef struct
+{
+    NUMBER value;
+    VALUE_TYPE type;
+} VALUE;
+
+typedef struct
+{
+    OPCODE opcode;
+    VALUE v1;
+    VALUE v2;
+} INSTRUCTION;
+
+void print_instruction(INSTRUCTION instruction)
+{
+    printf("%s\t|", OPCODE_STRINGS[instruction.opcode]);
+    if (instruction.v1.type == VARIABLE)
+        putchar(instruction.v1.value + 'w');
+    else
+        printf("%li", instruction.v1.value);
+    putchar('\t');
+    if (instruction.v2.type == VARIABLE)
+        putchar(instruction.v2.value + 'w');
+    else
+        printf("%li", instruction.v2.value);
+    putchar('\n');
+}
+
+#define CRASH(condition)                   \
+    if (condition)                         \
+    {                                      \
+        printf("CRASH AT %d\n", __LINE__); \
+        exit(EXIT_FAILURE);                \
+    }
+
+NUMBER run_program(INSTRUCTION *program, NUMBER program_size, NUMBER *rom)
+{
+
+    NUMBER rom_ptr = 0;
+    NUMBER registers[4] = {0};
+
+#define GET_VALUE(instruction, registers) (instruction.v2.type == VARIABLE ? registers[instruction.v2.value] : instruction.v2.value)
+    for (NUMBER i = 0; i < program_size; i++)
+    {
+        INSTRUCTION instruction = program[i];
+        CRASH(instruction.v1.type == UNDEFINED);
+        CRASH(instruction.v1.type != VARIABLE);
+        switch (instruction.opcode)
+        {
+        case INP:
+            registers[instruction.v1.value] = rom[rom_ptr];
+            rom_ptr++;
+            break;
+        case ADD:
+            CRASH(instruction.v2.type == UNDEFINED);
+            registers[instruction.v1.value] += GET_VALUE(instruction, registers);
+            break;
+        case MUL:
+            CRASH(instruction.v2.type == UNDEFINED);
+            registers[instruction.v1.value] *= GET_VALUE(instruction, registers);
+            break;
+        case DIV:
+            CRASH(instruction.v2.type == UNDEFINED);
+            CRASH(instruction.v2.value == 0);
+            registers[instruction.v1.value] /= GET_VALUE(instruction, registers);
+            break;
+        case MOD:
+            CRASH(instruction.v2.type == UNDEFINED);
+            CRASH(instruction.v2.value <= 0);
+            registers[instruction.v1.value] %= GET_VALUE(instruction, registers);
+            break;
+        case EQL:
+            CRASH(instruction.v2.type == UNDEFINED);
+            registers[instruction.v1.value] = (registers[instruction.v1.value] == GET_VALUE(instruction, registers));
+            break;
+        default:
+            break;
+        }
+    }
+#undef GET_VALUE
+    return registers[3];
+}
+
+int main(int argc, char const *argv[])
+{
+    FILE *p_file = fopen("input", "r");
+    char buf[BUFSIZ];
+    INSTRUCTION program[PROGRAM_SIZE];
+    NUMBER program_size = 0;
+
+#define STR2VALUE(token, instruction, val)                                                    \
+    token = strtok(NULL, " ");                                                                \
+    if (token != NULL)                                                                        \
+    {                                                                                         \
+        (instruction).val.type = (isdigit(token[0]) || token[0] == '-') ? LITERAL : VARIABLE; \
+        if ((instruction).val.type == VARIABLE)                                               \
+            (instruction).val.value = token[0] - 'w';                                         \
+        else                                                                                  \
+            (instruction).val.value = strtol(token, NULL, 0);                                 \
+    }
+
+    while (fgets(buf, sizeof buf, p_file) != NULL)
+    {
+        // READ INSTRUCTION
+        buf[strcspn(buf, "\n")] = '\0'; // DELETE TRAILING \n
+
+        char *token = strtok(buf, " ");
+        program[program_size].opcode = str2opcode(token);
+        STR2VALUE(token, program[program_size], v1);
+        STR2VALUE(token, program[program_size], v2);
+#undef STR2VALUE
+        program_size++;
+    }
+
+    return 0;
+}