Day21

day21/monkeysagain.c

@@ -0,0 +1,162 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <limits.h>
+
+#define BUFFER_SIZE 64
+#define MAX_MONKEYS 4096
+
+enum monkeyType {
+    CONSTANT,
+    ARITHMETIC
+};
+
+enum operand {
+    ADDITION,
+    SUBTRACTION,
+    MULTIPLICATION,
+    DIVISION
+};
+
+typedef struct monkey {
+    char name[4];
+    char leftOperandName[4];
+    char rightOperandName[4];
+    enum monkeyType type;
+    struct monkey *leftOperand;
+    struct monkey *rightOperand;
+    enum operand op;
+    long long number;
+    int hasValue;
+} MONKEY;
+
+long long getNumber(MONKEY);
+
+int main() {
+    char buf[BUFFER_SIZE], *p, c;
+    memset(buf, 0, BUFFER_SIZE);
+    p = buf;
+    MONKEY monkeys[MAX_MONKEYS], root;
+    memset(monkeys, 0, MAX_MONKEYS * sizeof(MONKEY));
+    int monkey_count = 0;
+    char op;
+
+    while ((c = getchar()) != EOF) {
+        *p++ = c;
+        if (c == '\n') {
+            if (sscanf(buf, "%c%c%c%c: %c%c%c%c %c %c%c%c%c", &monkeys[monkey_count].name[0], &monkeys[monkey_count].name[1], &monkeys[monkey_count].name[2], &monkeys[monkey_count].name[3], &monkeys[monkey_count].leftOperandName[0], &monkeys[monkey_count].leftOperandName[1], &monkeys[monkey_count].leftOperandName[2], &monkeys[monkey_count].leftOperandName[3], &op, &monkeys[monkey_count].rightOperandName[0], &monkeys[monkey_count].rightOperandName[1], &monkeys[monkey_count].rightOperandName[2], &monkeys[monkey_count].rightOperandName[3]) == 13) {
+                switch (op) {
+                    case '+':
+                        monkeys[monkey_count].op = ADDITION;
+                        break;
+                    case '-':
+                        monkeys[monkey_count].op = SUBTRACTION;
+                        break;
+                    case '*':
+                        monkeys[monkey_count].op = MULTIPLICATION;
+                        break;
+                    case '/':
+                        monkeys[monkey_count].op = DIVISION;
+                        break;
+                }
+                monkeys[monkey_count].type = ARITHMETIC;
+            } else {
+                sscanf(buf, "%c%c%c%c: %lli", &monkeys[monkey_count].name[0], &monkeys[monkey_count].name[1], &monkeys[monkey_count].name[2], &monkeys[monkey_count].name[3], &monkeys[monkey_count].number);
+                monkeys[monkey_count].type = CONSTANT;
+                monkeys[monkey_count].hasValue = 1;
+            }
+            monkey_count++;
+            memset(buf, 0, BUFFER_SIZE);
+            p = buf;
+        }
+    }
+    // Change names to pointers in monkeys
+    for (int i = 0; i < monkey_count; i++) {
+        if (monkeys[i].type == ARITHMETIC) {
+            for (int j = 0; j < monkey_count; j++) {
+                if (monkeys[i].leftOperandName[0] == monkeys[j].name[0] && monkeys[i].leftOperandName[1] == monkeys[j].name[1] && monkeys[i].leftOperandName[2] == monkeys[j].name[2] && monkeys[i].leftOperandName[3] == monkeys[j].name[3]) {
+                    monkeys[i].leftOperand = &monkeys[j];
+                }
+                if (monkeys[i].rightOperandName[0] == monkeys[j].name[0] && monkeys[i].rightOperandName[1] == monkeys[j].name[1] && monkeys[i].rightOperandName[2] == monkeys[j].name[2] && monkeys[i].rightOperandName[3] == monkeys[j].name[3]) {
+                    monkeys[i].rightOperand = &monkeys[j];
+                }
+            }
+        }
+    }
+
+    // Get the shouted number
+    //
+    // Find 'root'
+    for (int i = 0; i < monkey_count; i++) {
+        if (monkeys[i].name[0] == 'r' && monkeys[i].name[1] == 'o' && monkeys[i].name[2] == 'o' && monkeys[i].name[3] == 't') {\
+            root = monkeys[i];
+        }
+    }
+    printf("%lli\n", getNumber(root));
+
+    // Good old bruteforce for part 2
+    // Find human
+    MONKEY *human;
+    for (int i = 0; i < monkey_count; i++) {
+        if (monkeys[i].name[0] == 'h' && monkeys[i].name[1] == 'u' && monkeys[i].name[2] == 'm' && monkeys[i].name[3] == 'n') {\
+            human = &monkeys[i];
+        }
+    }
+
+    long long myNumber = 3759566892641;
+    human->hasValue = 1;
+    human->type = CONSTANT;
+    human->number = myNumber;
+    int found = 0;
+
+    printf("%lli, %lli\n", getNumber(*root.leftOperand), getNumber(*root.rightOperand));
+    printf("%lli\n", myNumber);
+//    do {
+//        // Reset all arithmetic monkeys
+//        for (int i = 0; i < monkey_count; i++) {
+//            if (monkeys[i].type == ARITHMETIC) {
+//                monkeys[i].hasValue = 0;
+//            }
+//        }
+//        human->number = myNumber++;
+//        long long left = getNumber(*root.leftOperand);
+//        // Reset all arithmetic monkeys
+//        for (int i = 0; i < monkey_count; i++) {
+//            if (monkeys[i].type == ARITHMETIC) {
+//                monkeys[i].hasValue = 0;
+//            }
+//        }
+//        long long right = getNumber(*root.rightOperand);
+//
+//        found = left == right;
+//    } while (!found); 
+//
+//    printf("%lli\n", myNumber-1);
+}
+
+long long getNumber(MONKEY monkey) {
+    // If previuosly calculated or constant
+    if (monkey.hasValue == 1) {
+        return monkey.number;
+    }
+
+    long long result = 0;
+    switch (monkey.op) {
+        case ADDITION:
+            result = getNumber(*monkey.leftOperand) + getNumber(*monkey.rightOperand);
+            break;
+        case SUBTRACTION:
+            result = getNumber(*monkey.leftOperand) - getNumber(*monkey.rightOperand);
+            break;
+        case MULTIPLICATION:
+            result =  getNumber(*monkey.leftOperand) * getNumber(*monkey.rightOperand);
+            break;
+        case DIVISION:
+            result = getNumber(*monkey.leftOperand) / getNumber(*monkey.rightOperand);
+            break;
+    }
+
+    monkey.hasValue = 1;
+    monkey.number = result;
+    return result;
+}