ize == 0){
            printf("%s[0]=\n", name);
            return;
        }
        printf("%s[%d]=", name, size);
        printf("(");
        printf("{%c,%.4f}", tokens[0].type, tokens[0].value);
        for(int i=1; i<size; i++){
            printf(", {%c,%.4f}", tokens[i].type, tokens[i].value);
        }
        printf(")\n");
    }
};

/*
 * 归约函数, 从操作数栈和操作符栈各弹出一个元素,
 * 与操作数栈顶的元素(并未弹出)运算后, 结果存在操作栈顶的元素中.
 */
void calculate(ArrayStack &operandStack, ArrayStack &operatorStack){
    if(operandStack.getSize() < 2){
        return;
    }
    Token *t1 = operandStack.pop();
    Token *t2 = operandStack.peek();
    Token *op = operatorStack.pop();
    switch(op->type){
        case ''*'':
            t2->value *= t1->value;
            break;
        case ''/'':
            t2->value /= t1->value;
            break;
        case ''+'':
            t2->value += t1->value;
            break;
        case ''-'':
            t2->value -= t1->value;
            break;
        default:
            printf("*********Syntax Error!*********\n");
            exit(1);
            break;
    }
}

int main(int argc, char *argv){
    char buffer[256];
    if(argc > 1){
        strcpy(buffer, argv);
    }else{
        printf("Input the statement(1-256 characters):\n");
        scanf("%s", buffer);
    }

    ArrayStack operan