Create compiler.c

compiler.c

@@ -0,0 +1,84 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <ctype.h>
+
+int expr();
+int term();
+int factor();
+void error();
+
+char token;
+
+void next_token() {
+    token = getchar();
+}
+
+void match(char expected_token) {
+    if (token == expected_token) {
+        next_token();
+    } else {
+        error();
+    }
+}
+
+void error() {
+    printf("Syntax error\n");
+    exit(1);
+}
+
+int expr() {
+    int result = term();
+    while (token == '+' || token == '-') {
+        char op = token;
+        next_token();
+        if (op == '+') {
+            result += term();
+        } else {
+            result -= term();
+        }
+    }
+    return result;
+}
+
+int term() {
+    int result = factor();
+    while (token == '*' || token == '/') {
+        char op = token;
+        next_token();
+        if (op == '*') {
+            result *= factor();
+        } else {
+            int divisor = factor();
+            if (divisor != 0) {
+                result /= divisor;
+            } else {
+                error();
+            }
+        }
+    }
+    return result;
+}
+
+int factor() {
+    int result;
+    if (isdigit(token)) {
+        ungetc(token, stdin);
+        scanf("%d", &result);
+        next_token();
+    } else if (token == '(') {
+        next_token();
+        result = expr();
+        match(')');
+    } else {
+        error();
+    }
+    return result;
+}
+
+int main() {
+    printf("Enter an arithmetic expression: ");
+    next_token();
+    int result = expr();
+    printf("Result: %d\n", result);
+    return 0;
+}