last lab

labPython/lab5/Spis22.py

@@ -0,0 +1,59 @@
+def evaluate(expr: str) -> int:
+    expr = expr.replace(" ", "")
+    pos = 0
+    
+    def number():
+        nonlocal pos
+        start = pos
+        if pos < len(expr) and expr[pos] in '+-':
+            pos += 1
+        while pos < len(expr) and expr[pos].isdigit():
+            pos += 1
+        return int(expr[start:pos])
+    
+    def factor():
+        nonlocal pos
+        if pos < len(expr) and expr[pos] == '(':
+            pos += 1
+            result = expression()
+            if pos >= len(expr) or expr[pos] != ')':
+                raise ValueError
+            pos += 1
+            return result
+        return number()
+    
+    def term():
+        nonlocal pos
+        result = factor()
+        while pos < len(expr) and expr[pos] in '*/':
+            op = expr[pos]
+            pos += 1
+            if op == '*':
+                result *= factor()
+            else:
+                num = factor()
+                if num == 0:
+                    raise ValueError
+                result //= num
+        return result
+    
+    def expression():
+        nonlocal pos
+        result = term()
+        while pos < len(expr) and expr[pos] in '+-':
+            op = expr[pos]
+            pos += 1
+            if op == '+':
+                result += term()
+            else:
+                result -= term()
+        return result
+    
+    result = expression()
+    if pos < len(expr):
+        raise ValueError
+    return result
+
+
+expr = input()
+print(evaluate(expr))