From 8a4c85625cdde8f732b02fea306839908855482a Mon Sep 17 00:00:00 2001
From: Joss <joss@jossco.de>
Date: Wed, 18 Sep 2024 11:48:00 +0200
Subject: [PATCH] Initial Commit

---
 main.c | 175 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 175 insertions(+)
 create mode 100644 main.c

diff --git a/main.c b/main.c
new file mode 100644
index 0000000..76b2372
--- /dev/null
+++ b/main.c
@@ -0,0 +1,175 @@
+#include <stdio.h>
+#include <stdbool.h>
+#include <string.h>
+#include <assert.h>
+#include <stdint.h>
+#include <math.h>
+
+
+bool SolveFor(char* func, uint32_t vars, uint8_t* varMap)
+{
+	char stack[1024];
+	int  stackPtr;
+	int  ptr;
+	bool valueA;
+	bool valueB;
+
+	stackPtr = 0;
+	ptr = 0;
+
+	while (func[ptr] != 0)
+	{
+		switch (func[ptr])
+		{
+			case '~':
+			{
+				assert(stackPtr > 0);
+				valueA = stack[stackPtr - 1];
+				stack[stackPtr-1] = !valueA;
+				break;
+			}
+
+			case '&':
+			{
+				assert(stackPtr > 1);
+
+				valueA = stack[--stackPtr];
+				valueB = stack[stackPtr-1];
+
+				stack[stackPtr - 1] = valueA && valueB;
+				break;
+			}
+
+			case '|':
+			{
+				assert(stackPtr > 1);
+
+				valueA = stack[--stackPtr];
+				valueB = stack[stackPtr-1];
+
+				stack[stackPtr - 1] = valueA || valueB;
+				break;
+			}
+
+			default:
+			{
+				if (func[ptr] == '0') stack[stackPtr++] = 0;
+				else if (func[ptr] == '1') stack[stackPtr++] = 1;
+				else if (func[ptr] >= 'a' && func[ptr] <= 'z')
+				{
+					assert(varMap[func[ptr] - 'a'] != 255);
+					stack[stackPtr++] = (vars >> varMap[func[ptr] - 'a']) & 0x01;
+				}
+				else assert(false);
+				break;
+			}
+		}
+		ptr++;
+	}
+
+	assert(stackPtr == 1);
+	return stack[stackPtr-1] != 0;
+}
+
+int main(int argc, char** argv)
+{
+	char* formula = "p&q|a&b&~d&c|e&f|x&y|z|g&h&i&j";
+	int   ptr;
+	char  stack[1024];
+	char  output[1024];
+	int   stackPtr;
+	int   outPtr;
+	int   varCount;
+	uint8_t varMap[26];
+	
+	ptr = 0;
+	stackPtr = 0;
+	outPtr = 0;
+	memset(varMap, 255, 26);
+	varCount = 0;
+
+	while(formula[ptr] != 0)
+	{
+		switch (formula[ptr])
+		{
+			case '~':
+			{
+				stack[stackPtr] = formula[ptr];
+				stackPtr++;
+				break;
+			}
+
+			case '&':
+			{
+				if (stackPtr > 0 && stack[stackPtr-1] == '~')
+				{
+					output[outPtr++] = stack[--stackPtr];
+				}
+
+				stack[stackPtr] = formula[ptr];
+				stackPtr++;
+				break;
+			}
+
+			case '|':
+			{
+				if (stackPtr > 0)
+				{
+					output[outPtr++] = stack[--stackPtr];
+				}
+
+				stack[stackPtr] = formula[ptr];
+				stackPtr++;
+				break;
+			}
+
+			default:
+			{
+				if (formula[ptr] >= 'a' && formula[ptr] <= 'z')
+				{
+					/** we got a variable **/
+					output[outPtr] = formula[ptr];
+					outPtr++;
+					if (varMap[formula[ptr] - 'a'] == 255)
+						varMap[formula[ptr] - 'a'] = varCount++;
+				}
+				else if (formula[ptr] == '0' || formula[ptr] == '1')
+				{
+					output[outPtr] = formula[ptr];
+					outPtr++;
+				}
+				else
+				{
+					printf("Unknown symbol %c!\n", formula[ptr]);
+					assert(false);
+				}
+			}
+		}
+		ptr++;
+	}
+
+	while (stackPtr > 0)
+	{
+		output[outPtr++] = stack[--stackPtr];
+	}
+
+	output[outPtr] = 0;
+
+	// print pretty header
+	for (int i = 0; i < 26; i++)
+		if (varMap[i] != 255)
+			printf("%c ", 'a'+i);
+	printf("Result\n");
+
+	// dirty hack
+	for (uint32_t i = 0; i < pow(2, varCount); i++)
+	{
+		// pretty printing
+		for (int j = 0; j < 26; j++)
+			if (varMap[j] != 255)
+				printf("%i ", (i >> varMap[j]) & 0x01);
+		printf("%i\n", SolveFor(output, i, varMap));
+	}
+
+	return 0;
+}