GMS Linux: start?

userprog/bracket/Makefile

@@ -0,0 +1,15 @@
+TARGET = bracket
+SRCS = bracket.c
+CC = gcc
+CFLAGS = -static -Wall
+
+OUT_BIN ?= $(TARGET)
+
+all: $(OUT_BIN)
+
+$(OUT_BIN): $(SRCS)
+	@echo "   [CC] Compiling to $(OUT_BIN)..."
+	$(CC) $(CFLAGS) -o $@ $^
+
+clean:
+	rm -f $(TARGET)

userprog/bracket/bracket.c

@@ -0,0 +1,108 @@
+#include <stdio.h>
+#include <string.h>
+#include <stdbool.h>
+#include <stdint.h>
+
+#define MAX_ITEMS 1024
+#define ITEMS_PER_WORD 16
+
+typedef struct {
+    uint32_t data[MAX_ITEMS / ITEMS_PER_WORD]; 
+    int top;
+} BitStack;
+
+void init_stack(BitStack *s) {
+    s->top = 0;
+    memset(s->data, 0, sizeof(s->data));
+}
+
+int encode(char c) {
+    switch(c) {
+        case '(': return 0;
+        case '{': return 1;
+        case '[': return 2;
+        default: return 3;
+    }
+}
+
+char decode(int code) {
+    switch(code) {
+        case 0: return '(';
+        case 1: return '{';
+        case 2: return '[';
+        default: return '?';
+    }
+}
+
+bool push(BitStack *s, char c) {
+    if (s->top >= MAX_ITEMS) return false;
+
+    int code = encode(c);
+    int word_idx = s->top / ITEMS_PER_WORD;
+    int bit_offset = (s->top % ITEMS_PER_WORD) * 2;
+
+    s->data[word_idx] &= ~((uint32_t)0x3 << bit_offset);
+    s->data[word_idx] |= ((uint32_t)code << bit_offset);
+
+    s->top++;
+    return true;
+}
+
+char pop(BitStack *s) {
+    if (s->top <= 0) return '\0';
+
+    s->top--;
+
+    int word_idx = s->top / ITEMS_PER_WORD;
+    int bit_offset = (s->top % ITEMS_PER_WORD) * 2;
+    int code = (s->data[word_idx] >> bit_offset) & 0x3;
+
+    return decode(code);
+}
+
+bool is_empty(BitStack *s) {
+    return s->top == 0;
+}
+
+bool check_bracket(char *str) {
+    BitStack s;
+    init_stack(&s);
+
+    int len = strlen(str);
+    for (int i = 0; i < len; i++) {
+        char ch = str[i];
+
+        if (ch == '(' || ch == '{' || ch == '[') {
+            if (!push(&s, ch)) {
+                printf("Error: Stack Overflow\n");
+                return false;
+            }
+        } 
+        else if (ch == ')' || ch == '}' || ch == ']') {
+            if (is_empty(&s)) return false;
+
+            char open_ch = pop(&s);
+            
+            if (ch == ')' && open_ch != '(') return false;
+            if (ch == '}' && open_ch != '{') return false;
+            if (ch == ']' && open_ch != '[') return false;
+        }
+    }
+
+    return is_empty(&s);
+}
+
+int main(int argc, char *argv[]) {
+    if (argc != 2) {
+        printf("Usage: bracket <string>\n");
+        return 1;
+    }
+
+    if (check_bracket(argv[1])) {
+        printf("Valid\n");
+        return 0;
+    } else {
+        printf("Invalid\n");
+        return 1;
+    }
+}