import java.util.Scanner; // 注意类名必须为 Main, 不要有任何 package xxx 信息 import javax.script.ScriptEngine; import javax.script.ScriptEngineFactory; import javax.script.ScriptEngineManager; import javax.script.ScriptException; import java.util.Scanner; public class Main { public static void main(String[] args) throws ScriptException { Scanner scanner = new Scanner(System.in); String express = scanner.nextLine(); ScriptEngine scriptEngine = new ScriptEngineManager().getEngineByName("javascript"); express = express.replace("{", "("); express = express.replace('}', ')'); express = express.replace('[', '('); express = express.replace(']', ')'); System.out.println(scriptEngine.eval(express)); } } 这个可以处理1/-3这种特殊场景的，但是你这个算法无法处理这种特殊场景的